R-858: after a Docker engine step the wrapper restarts ONLY the containers that mount the docker socket (controller, traefik); the health rule fails when the controller cannot reach Docker from inside its container (ruling 95)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

CHANGELOG.md

@@ -1,3 +1,96 @@
+## v0.142.0 — the Docker engine slow lane, the version report, the crash guard (`11` §5.8, §5.9; `09` decisions 87–89)
+
+> **RELEASED 2026-10-04** by `scripts/release-agent.sh` — tag `v0.142.0` (`b1746c2`), sha256
+> `7beb32224d6495e9561acfd3ad8a48393a799520f196080011cb27fceb6d1de6`, verified by download. Not vouched at release time.
+
+**MinAgent impact:** none. **Needs hub v0.132.0** for the System page, the Docker approval and the crash events; an older
+hub stores the new `system` stanza unread. **Needs the new root files** on an installed box (R-840): the wrapper,
+`/etc/felhom/os-trust.json`, `/etc/felhom/operator-signers` and the crash guard — the installer 1.30.0 writes them; the
+demo boxes got them by hand.
+
+- **Docker `live-restore` ON** (decision 87). Wrapper mode `live-restore-on`: merge `"live-restore": true` into the
+  guest's `/etc/docker/daemon.json` and `systemctl reload docker` — never a restart (R-835). An invalid daemon.json is
+  left alone (R16); a reload that does not enable it puts the old file back. The leg runs it once before a Docker step;
+  `--selftest=live-restore -vmid N` runs it by hand. Measured: demo-hp 24 containers, demo-felhom 5 — the same ids after.
+- **The Docker engine slow lane** (`11` §5.8). Wrapper layer `docker`, lane `slow` only, the six Docker packages only,
+  origin `Docker CE` only (R2; a Docker package in a fast-lane plan is refused). **R3 — the wrapper checks the authority
+  itself**, never the agent's config: a ring-1 step or ANY undo needs a signed `os_docker_step` it verifies with
+  `ssh-keygen -Y verify` against the ROOT-owned `/etc/felhom/operator-signers` (namespace `felhom-op-v1`, the blob's
+  `key_id`), bound to `/etc/felhom/os-trust.json` `host_id`, inside its time window, never replayed (a root-owned nonce
+  file), with exactly the signed packages and undo flag; an unsigned ring-0 step needs that file's
+  `"ring0_slow_lane": true` (the demo boxes only, set by hand). **R15:** live-restore must be on. An undo may downgrade
+  (`--allow-downgrades`) only inside a signed job. The leg: ring 0 runs the Docker step at night after a healthy guest
+  and host step (`select pending-docker`); ring 1 never does — only `DockerStepExecutor` (signed job, heavy-op gate).
+  **Health:** the guest rule + every container running at the start has the SAME id after + the engine reports the
+  installed version; a changed id is `health_failed`. Measured ring 0: 29.7.x → 29.8.2 on both demo boxes, every id kept.
+- **The version report** (R-852, decision 89). Wrapper mode `facts` (read-only): host Debian, running and next-boot
+  kernel (`next_entry` > saved default > newest installed, by dpkg order), held packages (R-848), kernel taint (oops,
+  warn), `kernel.panic`, the crash guard state; guest Debian, Docker engine, containerd, live-restore. The host report
+  gains `system {pve_version, kernel_version, vmid, facts, facts_error}`, read at most every 10 min (~2 s);
+  `--selftest=os-facts -vmid N`. A value nobody could read is `unknown`.
+- **R-849:** the guest is scanned for "restart needed" on every pass too, so a guest restart clears it.
+- **The crash guard** (decision 88, R-851): `configs/felhom-crash-guard` + `felhom-crash-guard.service` (early boot;
+  its ExecStop writes a clean-stop marker) + an hourly re-arm timer + `/etc/felhom/crash-guard.conf`. A boot without
+  the marker followed an unclean stop (a crash, a power cut or a hard reset — pstore saved nothing for a real panic on
+  demo-hp, so they cannot be told apart). Armed: `kernel.panic = 10`. After the 2nd unclean boot within 60 min it
+  TRIPS (`kernel.panic = 0`), so the 3rd crash within the hour leaves the box off; it re-arms after 24 h of normal
+  running or `felhom-crash-guard rearm`. State in `/var/lib/felhom-crash-guard/state.json` (0644; read by facts).
+- **After the tag (main only, not shipped to boxes): `configs/build-golden.sh` 3.1.0** — the golden's `daemon.json`
+  carries `"live-restore": true` with a fail-closed assertion, and `GOLDEN_DOCKER_PKGS` pins the approved Docker engine
+  set (all six `name=version`); without it the bake log warns that the set is the newest, not an approved one.
+- Tests: wrapper 76 (DockerLane, LiveRestore, Facts, RealSignatureCheck with a throwaway key), crash guard 9, Go leg +
+  executor; red-proofs `felhom.eu/documentation/audits/os-docker-crash-2026-10-04/partB/agent-redproofs.txt` (17 caught).
+
+## v0.141.1 — "reboot needed" is true on the host (found live on demo-felhom, 2026-10-04)
+
+> **RELEASED 2026-10-04** by `scripts/release-agent.sh` — tag `v0.141.1` (`a6bc3f1`), sha256
+> `b712f577099fd2d374f648df1e825874821302fe1b46e93c7b4b70044fbe84b5`, verified by download. Not vouched at release time.
+
+**MinAgent impact:** none. **Pairs with hub v0.131.1** (reads `reboot_scanned`); an older hub ignores the field.
+
+A patch release in the same session as v0.141.0 — a deliberate exception to "one release per repo": v0.141.0's host
+"reboot needed" was wrong in two ways, and it feeds an operator alarm.
+- **The scan hid `lxc-start`.** The host scan skipped every process whose cgroup line contains `lxc`, to leave out the
+  guests' own processes. `lxc-start` lives in `0::/lxc.monitor/<vmid>`, so it was skipped too. Measured: after a
+  108-package host pass (libc6 included) `lxc-start` mapped 20 deleted files and the report said `reboot_needed:
+  false`. The pattern is now `:/lxc/` (`RESTART_SKIP_CGROUP`), pinned by a test that runs `grep` against the measured
+  cgroup lines.
+- **A reboot never cleared it.** v0.141.0 scanned only after an install (R-845). The host now scans on EVERY pass (it
+  is local, no `pct exec`); the guest still scans only after an install. The report carries `reboot_scanned`.
+- Red-proofs: `felhom.eu/documentation/audits/os-host-lane-2026-10-04/partB/live-defects-redproofs.txt`.
+
+## v0.141.0 — OS updates: the host fast lane (`11` §8 step 3); the tunnel status is true (R-841); the leg is fast (R-845)
+
+> **RELEASED 2026-10-04** by `scripts/release-agent.sh` — tag `v0.141.0` (`cfba0d0`), sha256
+> `6eaad9809613c4fca64aefc30cc16415528499bf48efe3a1daaa08af8a611aff`, verified by download. Not vouched at release time.
+
+**MinAgent impact:** none required by any controller. **Needs hub v0.131.0** (`host_release`, the tunnel's three
+states, layer-tagged OS reports). With an older hub the host step finds no host release (ring 1 → nothing) and the
+tunnel's `detail` is ignored. Reads the cloudflared health check controller v0.292.0 adds; with an older controller
+the tunnel is judged on the container state alone and `detail` says so.
+
+- **R-841 — the tunnel.** The agent used to run `systemctl is-active cloudflared` on the HOST — a unit that does not
+  exist (cloudflared is a container in the customer guest), so every box reported `inactive`. `GuestTunnelProber`
+  now reads the guest's `cloudflared` container through the EXISTING sudoers line (`pct exec N -- docker inspect -f
+  *`): state, exit code, and the Docker health status. Three states: `running` (healthy), `not_running` (stopped,
+  absent, or running but NOT connected), `unknown` (could not ask, or the check is still starting). `detail` says why.
+- **The host step** (`11` §8 step 3). After a healthy guest step, under the same heavy-op gate, the leg runs the same
+  wrapper with `layer: host`. Debian origin only; never kernel, boot or firmware packages (new refusal **R14**);
+  **only on an appliance** (**R12** lifted for the host fast lane: proof is the ROOT-owned install record
+  `/var/lib/felhom-install/state.json` `mode: appliance` — the agent-writable `agent.json` is not trusted for this).
+  A failed or unhealthy guest step skips it. **Host health rule:** the agent, pveproxy, pvedaemon, pvestatd and
+  pve-cluster are active; the customer guest runs; the guest health rule passes; the tunnel is `running` (an
+  `unknown` tunnel does not fail the rule; `not_running` does). Never reboots: "reboot needed" is reported when PID 1
+  or `lxc-start` runs a replaced library. No automatic undo — the by-hand runbook is `os-updates-host-undo.md`.
+- **R-845 — the leg is fast.** The wrapper asked about each package in its own `pct exec` (about 0.9 s each). It now
+  makes one call per layer for the version checks (`apt-cache madison` for all names at once, `dpkg --compare-versions`
+  on the host), scans for restart-needed only after an install, repairs only when `dpkg --audit` reports something,
+  and reports its own `pass_seconds`.
+- **Wrapper tests:** `configs/test_felhom_os_apply.py` 46 tests (host layer, R12, R14, lxc-start, the speed rules).
+  Red-proofs: `felhom.eu/documentation/audits/os-host-lane-2026-10-04/partA/`, `partB/`, `partC/agent-golden-redproof.txt`.
+- **Contract:** the desired-state golden gains `host_release` (byte-identical with the hub's); `TestOSUpdateGolden_Decodes`
+  checks it.
+
 ## v0.140.0 — OS updates, guest fast lane (`11-os-updates.md` §8 step 2; `09` §3 decisions 76, 79, 80)
 
 > **RELEASED 2026-10-04** by `scripts/release-agent.sh` — tag `v0.140.0` (`9cac346`), sha256

REPORT.md

@@ -1,11 +1,9 @@
-# REPORT — 2026-10-04: v0.140.0, OS updates (guest fast lane)
+# REPORT — 2026-10-04: v0.142.0, Docker slow lane + version report + crash guard
 
-Full session report: `felhom.eu/REPORT-os-guest-lane-2026-10-04.md`.
+Full session report: `felhom.eu/REPORT-os-docker-crash-2026-10-04.md`.
 
-- `felhom-os-apply` wrapper (R1–R13, repair first, snapshot.debian.org fallback), `FELHOM_OSAPPLY` sudoers, the OS leg
-  after the primary backup, `--selftest=os-update`. Released `9cac346`, sha256 `ae2d60b7…1250`, verified by download.
-- Live on both demo boxes: ring 0 installed 53 packages each, healthy; ring 1 installed exactly the 3 approved versions;
-  a deliberately failed health check reported `health_failed` and mailed the operator.
-- Found and fixed live: the `--selftest` flag refused `os-update` (and `wgtunnel`, since S3); the conffile log line
-  called an updated file "kept"; an app stopped between the inventory and the apply escaped the health check.
-- No automatic undo (R-837: PVE refuses a snapshot of a guest with host-path binds).
+- Docker live-restore turned on by reload (never a restart); the Docker engine set as a slow lane whose authority the
+  root wrapper checks itself (signed job against a root-owned key file, or the root-owned ring-0 mark); same-id health.
+- The box reports its versions (Proxmox, kernels, Debian, Docker, live-restore, held packages, taint, crash guard).
+- The crash guard: a crashed host restarts, the 3rd unclean stop within an hour leaves it off, 24 h re-arm.
+- Tests and 17 red-proofs; live on both demo boxes (see the session report).

cmd/felhom-agent/main.go

@@ -44,11 +44,11 @@ import (
 	"gitea.dooplex.hu/admin/felhom-agent/internal/localapi"
 	applog "gitea.dooplex.hu/admin/felhom-agent/internal/log"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/mgmtplane"
+	"gitea.dooplex.hu/admin/felhom-agent/internal/osupdate"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/pbs"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/pbsdr"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/poke"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/provision"
-	"gitea.dooplex.hu/admin/felhom-agent/internal/osupdate"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/proxmox"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/reconcile"
 	"gitea.dooplex.hu/admin/felhom-agent/internal/restorespace"
@@ -245,6 +245,10 @@ func main() {
 		os.Exit(runSelftestRestoreTestDue(context.Background(), cfg, logger))
 	case "os-update":
 		os.Exit(runSelftestOSUpdate(context.Background(), cfg, logger, vmid))
+	case "os-facts":
+		os.Exit(runSelftestFacts(context.Background(), cfg, logger, vmid))
+	case "live-restore":
+		os.Exit(runSelftestLiveRestore(context.Background(), cfg, logger, vmid))
 	case "pbs-verify":
 		os.Exit(runSelftestPBSVerify(context.Background(), cfg, logger))
 	case "lanresolver":
@@ -845,6 +849,7 @@ func runDaemon(cfg config.Config, logger *slog.Logger, logRing *applog.Ring) int
 	// OS updates, guest fast lane (agent v0.140.0, `11-os-updates.md` §8 step 2): the leg consumes the hub's
 	// os_update block and runs after each successful primary whole-guest backup (wired on the local API below).
 	osLeg := newOSLeg(cfg, client, px, logger)
+	collector.SetSystemReporter(&factsReporter{leg: osLeg, guest: firstGuest(px)}) // R-852: the versions
 	desiredSyncer.AddConsumer(osLeg)
 	// S5: consume a host_loss restore_directive into an inspectable restore PLAN (derive + surface,
 	// execute nothing). The recipe is fetched on-demand (rare directive) via a fresh Collect.
@@ -1087,7 +1092,16 @@ func runDaemon(cfg config.Config, logger *slog.Logger, logRing *applog.Ring) int
 	// recurring clobber before it locks the box out. Port 22 for G1 (H1 passes the felhom-sshd port).
 	collector.SetMgmtPlaneReporter(mgmtplane.NewReporter(mgmtplane.DefaultPrivsepDir, mgmtplane.DefaultHealMarker, mgmtplane.DefaultSshdPort))
 
-	jobsRunner := signedjobs.NewRunner(client, gate, signedjobs.ExecutorChain{wipeExec, decommExec, updateExec}, cfg.Hub.HostID, logger)
+	// Agent v0.142.0: a signed Docker engine step (`11` §5.8) — ring 1 and every undo; under the heavy-op gate.
+	dockerExec := osupdate.DockerStepExecutor{Leg: osLeg, Guest: firstGuest(px),
+		Gate: func(ctx context.Context) (func(), error) {
+			release, busy, ok := heavyOps.TryAcquire("os-docker-step")
+			if !ok {
+				return nil, fmt.Errorf("busy: %s", busy)
+			}
+			return release, nil
+		}}
+	jobsRunner := signedjobs.NewRunner(client, gate, signedjobs.ExecutorChain{wipeExec, decommExec, updateExec, dockerExec}, cfg.Hub.HostID, logger)
 	loop.SetEnvelopeObserver(hub.MultiObserver(desiredSyncer, jobsRunner))
 
 	// Controller-driven escrow ceremony (v0.88.0): static config facts + the LATE-BOUND DR gate —
@@ -1127,7 +1141,7 @@ func runDaemon(cfg config.Config, logger *slog.Logger, logRing *applog.Ring) int
 				return
 			case <-time.After(90 * time.Second):
 			}
-			_, _ = osLeg.Run(ctx, vmid, "night")
+			_ = osLeg.Run(ctx, vmid, "night")
 		})
 	}
 	if localTokens != nil {
@@ -1869,7 +1883,7 @@ func buildLocalAPIServer(cfg config.Config, px *proxmox.Client, store *backup.St
 		ConfigPath:     cfg.SourcePath,
 		StateDir:       cfg.WGTunnel.WithDefaults().StateDir,
 		SmbCredsDir:    cfg.Privileged.SmbCredsDir,
-		ControllerSwap: guestBinder, // Phase 1: agentic controller update — in-guest image swap
+		ControllerSwap: guestBinder,                    // Phase 1: agentic controller update — in-guest image swap
 		GuestsStateDir: "/var/lib/felhom-agent/guests", // R-523: <vmid>/bootstrap + controller-parked marker
 		// F2-b: recover a guest left with a stale vzdump lock by a reboot-during-backup. Reads + start
 		// go through the API client; the `pct unlock` is the one fenced root-CLI op (no API equivalent).
@@ -3498,10 +3512,12 @@ func (f *selftestFlag) Set(v string) error {
 		f.mode = "controller-swap"
 	case "os-update":
 		f.mode = "os-update"
+	case "os-facts", "live-restore": // agent v0.142.0
+		f.mode = v
 	case "wgtunnel": // dispatched since S3 but refused here until 2026-10-04 (TestSelftestFlag_AcceptsEveryDispatchedMode)
 		f.mode = "wgtunnel"
 	default:
-		return fmt.Errorf("invalid --selftest value %q (want read|task|hub|storage|backup|restore-test|restore-test-due|pbs-verify|lanresolver|wgtunnel|bring-up|provision|escrow-create|escrow-consume|identity-consume|controller-swap|os-update)", v)
+		return fmt.Errorf("invalid --selftest value %q (want read|task|hub|storage|backup|restore-test|restore-test-due|pbs-verify|lanresolver|wgtunnel|bring-up|provision|escrow-create|escrow-consume|identity-consume|controller-swap|os-update|os-facts|live-restore)", v)
 	}
 	return nil
 }
@@ -3558,29 +3574,71 @@ func runSelftestOSUpdate(ctx context.Context, cfg config.Config, logger *slog.Lo
 	fmt.Printf("=== felhom-agent %s selftest=os-update vmid=%d ring=%d enabled=%v guest-release=%v host-release=%v appliance=%v ===\n",
 		version, vmid, b.Ring, b.Enabled, b.Release != nil, b.HostRelease != nil, leg.Appliance)
 	start := time.Now()
-	g, h := leg.Run(ctx, vmid, "debug")
-	for _, rep := range []osupdate.Report{g, h} {
+	pass := leg.Run(ctx, vmid, "debug")
+	worst := pass.Guest
+	for i, rep := range []osupdate.Report{pass.Guest, pass.Host, pass.Docker} {
 		if rep.Layer == "" {
-			fmt.Println("  host step: skipped (see the log line above)")
+			fmt.Printf("  %s step: skipped (see the log line above)\n", []string{"guest", "host", "docker"}[i])
 			continue
 		}
 		printJSON("os-update report ("+rep.Layer+")", map[string]any{"run_id": rep.RunID, "ring": rep.Ring, "release_id": rep.ReleaseID,
 			"mode": rep.Mode, "outcome": rep.Outcome, "healthy": rep.Healthy, "health_reason": rep.HealthReason,
 			"upgraded": rep.Upgraded, "pending": len(rep.Pending), "not_covered": rep.NotCovered,
-			"restart_needed": rep.RestartNeeded, "reboot_needed": rep.RebootNeeded, "wrapper_seconds": rep.PassSeconds, "refused": rep.Refused})
+			"restart_needed": rep.RestartNeeded, "reboot_needed": rep.RebootNeeded, "wrapper_seconds": rep.PassSeconds,
+			"refused": rep.Refused, "docker_engine": rep.DockerEngine, "authority": rep.Authority})
+		if !(rep.Outcome == "applied" || rep.Outcome == "nothing" || rep.Outcome == "inventory" || rep.Outcome == "skipped") {
+			worst = rep
+		}
 	}
 	fmt.Printf("  pass took %s\n", time.Since(start).Round(100*time.Millisecond))
-	rep := g
-	if h.Layer != "" && !(h.Outcome == "applied" || h.Outcome == "nothing" || h.Outcome == "inventory") {
-		rep = h
-	}
-	switch rep.Outcome {
+	switch worst.Outcome {
 	case "applied", "nothing", "inventory", "skipped":
 		return 0
 	}
 	return 1
 }
 
+// runSelftestFacts prints the versions the host report carries (R-852, agent v0.142.0) — read-only.
+//
+//	sudo -u felhom-agent felhom-agent --config … --selftest=os-facts -vmid 9201
+func runSelftestFacts(ctx context.Context, cfg config.Config, logger *slog.Logger, vmid int) int {
+	if vmid <= 0 {
+		fmt.Fprintln(os.Stderr, "selftest=os-facts: -vmid is required")
+		return 2
+	}
+	px, _ := newProxmoxClient(cfg)
+	leg := newOSLeg(cfg, nil, px, logger)
+	start := time.Now()
+	f, err := leg.Facts(ctx, vmid)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "selftest=os-facts:", err)
+		return 1
+	}
+	var v any
+	_ = json.Unmarshal(f, &v)
+	printJSON(fmt.Sprintf("facts (vmid %d, %s)", vmid, time.Since(start).Round(100*time.Millisecond)), v)
+	return 0
+}
+
+// runSelftestLiveRestore is the ONE-TIME live-restore step (`09` decision 87) as a debug action — the night leg does
+// the same before a ring-0 Docker step. It prints the container ids before and after (they must not change).
+//
+//	sudo -u felhom-agent felhom-agent --config … --selftest=live-restore -vmid 9202
+func runSelftestLiveRestore(ctx context.Context, cfg config.Config, logger *slog.Logger, vmid int) int {
+	if vmid <= 0 {
+		fmt.Fprintln(os.Stderr, "selftest=live-restore: -vmid is required")
+		return 2
+	}
+	px, _ := newProxmoxClient(cfg)
+	leg := newOSLeg(cfg, nil, px, logger)
+	if err := leg.EnsureLiveRestore(ctx, time.Now().UTC().Format("20060102T150405Z"), vmid); err != nil {
+		fmt.Fprintln(os.Stderr, "selftest=live-restore:", err)
+		return 1
+	}
+	fmt.Println("live-restore: on (see the wrapper's LIVE-RESTORE line above for the container ids)")
+	return 0
+}
+
 // newTunnelProber reads the box's REAL tunnel (R-841, agent v0.141.0): the cloudflared container in each running
 // customer guest — a guest that binds /mnt/felhom-drives, the same rule the OS wrapper's R10 uses — through the
 // existing `pct exec [0-9]* -- docker inspect -f *` sudoers line.
@@ -3591,31 +3649,80 @@ func newTunnelProber(cfg config.Config, px *proxmox.Client) hub.CloudflaredProbe
 	}
 	return hub.GuestTunnelProber{
 		Runner: &proxmox.ExecRunner{Mode: mode, SudoPath: cfg.Privileged.SudoPath},
-		Guests: func(ctx context.Context) ([]int, error) {
-			if px == nil {
-				return nil, fmt.Errorf("no proxmox client")
-			}
-			gs, err := px.ListLXC(ctx)
-			if err != nil {
-				return nil, err
-			}
-			var out []int
-			for _, g := range gs {
-				if g.Status != "running" {
-					continue
-				}
-				gc, err := px.GuestConfig(ctx, g.VMID)
-				if err != nil {
-					continue
-				}
-				for _, v := range gc.MountPoints() {
-					if src, _, _ := strings.Cut(v, ","); src == "/mnt/felhom-drives" {
-						out = append(out, g.VMID)
-						break
-					}
-				}
-			}
-			return out, nil
-		},
+		Guests: customerGuests(px),
 	}
 }
+
+// customerGuests lists the running guests that bind /mnt/felhom-drives — the box's customer guest(s), the same rule the
+// OS wrapper's R10 uses. Shared by the tunnel probe, the facts read and the signed Docker step.
+func customerGuests(px *proxmox.Client) func(ctx context.Context) ([]int, error) {
+	return func(ctx context.Context) ([]int, error) {
+		if px == nil {
+			return nil, fmt.Errorf("no proxmox client")
+		}
+		gs, err := px.ListLXC(ctx)
+		if err != nil {
+			return nil, err
+		}
+		var out []int
+		for _, g := range gs {
+			if g.Status != "running" {
+				continue
+			}
+			gc, err := px.GuestConfig(ctx, g.VMID)
+			if err != nil {
+				continue
+			}
+			for _, v := range gc.MountPoints() {
+				if src, _, _ := strings.Cut(v, ","); src == "/mnt/felhom-drives" {
+					out = append(out, g.VMID)
+					break
+				}
+			}
+		}
+		return out, nil
+	}
+}
+
+// firstGuest is the single customer guest (an error when there is none).
+func firstGuest(px *proxmox.Client) func(ctx context.Context) (int, error) {
+	f := customerGuests(px)
+	return func(ctx context.Context) (int, error) {
+		v, err := f(ctx)
+		if err != nil {
+			return 0, err
+		}
+		if len(v) == 0 {
+			return 0, fmt.Errorf("no running customer guest")
+		}
+		return v[0], nil
+	}
+}
+
+// factsReporter feeds the host report's `system` stanza (R-852, agent v0.142.0) from the wrapper's read-only facts
+// mode, at most every 10 minutes (each read is ~2 s of pct exec; the host reports every 15 min).
+type factsReporter struct {
+	leg   *osupdate.Leg
+	guest func(ctx context.Context) (int, error)
+	mu    sync.Mutex
+	at    time.Time
+	vmid  int
+	facts json.RawMessage
+	err   error
+}
+
+func (f *factsReporter) SystemFacts(ctx context.Context) (int, json.RawMessage, error) {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	if !f.at.IsZero() && time.Since(f.at) < 10*time.Minute {
+		return f.vmid, f.facts, f.err
+	}
+	f.at = time.Now()
+	f.vmid, f.err = f.guest(ctx)
+	if f.err != nil {
+		f.facts = nil
+		return 0, nil, f.err
+	}
+	f.facts, f.err = f.leg.Facts(ctx, f.vmid)
+	return f.vmid, f.facts, f.err
+}

configs/build-golden.sh

@@ -61,7 +61,7 @@ set -euo pipefail
 
 # Script provenance — logged into every bake transcript next to the baked controller tag, so an
 # archive can always be traced to the script that produced it. Bump on any behavior change.
-GOLDEN_SCRIPT_VERSION="3.0.0"
+GOLDEN_SCRIPT_VERSION="3.1.0"
 
 VMID="${1:-9100}"
 TEMPLATE="${2:-local:vztmpl/debian-13-standard_13.1-2_amd64.tar.zst}"
@@ -112,7 +112,15 @@ for i in $(seq 1 30); do
   if pct exec "$VMID" -- getent hosts download.docker.com >/dev/null 2>&1; then break; fi
   sleep 1
 done
-pct exec "$VMID" -- bash -c '
+# v3.1.0 (`11` §5.8): GOLDEN_DOCKER_PKGS pins the APPROVED Docker engine set (the hub's newest Docker release, all six
+# "name=version"); without it the newest stable set is installed and the bake log says so.
+GOLDEN_DOCKER_PKGS="${GOLDEN_DOCKER_PKGS:-}"
+if [[ -n "$GOLDEN_DOCKER_PKGS" ]]; then
+  echo "[golden] Docker engine set PINNED to the approved release: $GOLDEN_DOCKER_PKGS"
+else
+  echo "[golden] WARNING: GOLDEN_DOCKER_PKGS not set — installing the newest stable Docker set, not an approved one"
+fi
+pct exec "$VMID" -- env GOLDEN_DOCKER_PKGS="$GOLDEN_DOCKER_PKGS" bash -c '
   set -e
   export DEBIAN_FRONTEND=noninteractive
   apt-get update -qq
@@ -122,7 +130,12 @@ pct exec "$VMID" -- bash -c '
   echo "deb [signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian trixie stable" \
     > /etc/apt/sources.list.d/docker.list
   apt-get update -qq
-  apt-get install -y -qq docker-ce docker-ce-cli containerd.io >/dev/null
+  if [ -n "$GOLDEN_DOCKER_PKGS" ]; then
+    apt-get install -y -qq $GOLDEN_DOCKER_PKGS >/dev/null
+  else
+    apt-get install -y -qq docker-ce docker-ce-cli containerd.io >/dev/null
+  fi
+  dpkg-query -W containerd.io docker-buildx-plugin docker-ce docker-ce-cli docker-ce-rootless-extras docker-compose-plugin 2>/dev/null | sed "s/^/  installed: /"
 '
 echo "[golden] baking daemon.json: classic overlay2 driver (containerd-snapshotter OFF) + log rotation …"
 # containerd-snapshotter (Docker 28+/29 default) keeps the IMAGE content store under
@@ -135,9 +148,12 @@ echo "[golden] baking daemon.json: classic overlay2 driver (containerd-snapshott
 # layout (a container's `df /` reports the single volume, phase-0 spike). Since v3.0.0 /var/lib/docker
 # is a BIND of <volume>/docker rather than the mp0 mount itself, wired immediately below; data-root
 # still needs no override because the path is unchanged. Log caps kill the most common runaway.
+# v3.1.0: "live-restore": true (`09` decision 87) — a Docker engine update then restarts no app (`11` C5). A box made
+# from this golden never needs the agent's one-time live-restore-on step. NEVER removed by a plain restart (R-835).
 pct exec "$VMID" -- bash -c 'mkdir -p /etc/docker; cat > /etc/docker/daemon.json <<JSON
 {
   "features": { "containerd-snapshotter": false },
+  "live-restore": true,
   "log-driver": "json-file",
   "log-opts": { "max-size": "10m", "max-file": "3" }
 }
@@ -175,6 +191,8 @@ pct exec "$VMID" -- bash -c 'systemctl restart docker; sleep 3; docker run --rm
 # Guard: the image store MUST be on the data volume now. /var/lib/containerd holding the images would
 # mean containerd-snapshotter is still on (the split would leave images on the rootfs).
 pct exec "$VMID" -- bash -c 'drv=$(docker info 2>/dev/null | sed -n "s/.*Storage Driver: //p"); [ "$drv" = "overlay2" ] || { echo "[golden] FATAL: storage driver is $drv, expected overlay2 — images would not land on the data volume"; exit 1; }'
+# v3.1.0 ASSERTION: live-restore is ON in the running daemon (decision 87), or the bake fails closed.
+pct exec "$VMID" -- bash -c 'lr=$(docker info --format "{{.LiveRestoreEnabled}}" 2>/dev/null); [ "$lr" = "true" ] && echo "  live-restore: on" || { echo "[golden] FATAL: live-restore is $lr, expected true (decision 87)"; exit 1; }'
 # ASSERTION 1 (RETARGETED v3.0.0, not removed). /var/lib/docker must be a real mount — now the V-c
 # bind of <volume>/docker rather than the mp0 mount itself. Still fails closed on the same failure:
 # if the bind did not take, Docker's data-root silently sits on the OS rootfs and the golden ships

configs/crash-guard.conf

@@ -0,0 +1,8 @@
+# /etc/felhom/crash-guard.conf — read by /usr/local/sbin/felhom-crash-guard (`11` §5.9).
+# The LIMIT-th unclean stop within WINDOW_MINUTES leaves the box off. Decided by CC unattended — operator may reverse.
+LIMIT=3
+WINDOW_MINUTES=60
+# kernel.panic while armed: seconds after a crash before the kernel restarts the box.
+PANIC_SECONDS=10
+# A tripped guard re-arms after this many hours of normal running (or `felhom-crash-guard rearm`).
+REARM_HOURS=24

configs/felhom-crash-guard

@@ -0,0 +1,235 @@
+#!/usr/bin/python3
+# felhom-crash-guard — a crashed host restarts by itself, but not forever (`09` decision 88, R-851, `11` §5.9).
+#
+# Install as /usr/local/sbin/felhom-crash-guard (0755 root:root), with felhom-crash-guard.service (boot / clean-stop)
+# and felhom-crash-guard-check.timer (hourly re-arm check). Python 3, standard library only.
+# Tests: configs/test_felhom_crash_guard.py (temp dirs; nothing real is touched).
+#
+# WHAT IT DOES
+#   boot        early at every boot. Was the previous boot ended CLEANLY? (the clean-stop marker exists). If not, this
+#               boot follows an UNCLEAN stop — a kernel crash, a power cut or a hard reset (they cannot be told apart
+#               on these boxes: measured 2026-10-04 on demo-hp, efi_pstore is on yet saved NOTHING for a real panic;
+#               the journal and `last` show only "no shutdown"). It records the unclean boot, counts those in the last
+#               WINDOW_MINUTES, and sets kernel.panic:
+#                 - fewer than LIMIT-1 recent unclean boots → kernel.panic = PANIC_SECONDS (a crash restarts the box);
+#                 - LIMIT-1 or more → the guard TRIPS: kernel.panic = 0, so the LIMIT-th crash within the window
+#                   leaves the box OFF (operator's own words: "if it crashes 3 times within one hour, it stays off").
+#               A tripped guard stays tripped across further boots until it re-arms.
+#   clean-stop  ExecStop of the service: writes the clean-stop marker during an orderly shutdown or reboot.
+#   check       hourly: a tripped guard re-arms after REARM_HOURS of normal running (since the trip AND since boot).
+#   rearm       the operator re-arms by hand (`felhom-crash-guard rearm`).
+#   status      prints the state.
+# The state is /var/lib/felhom-crash-guard/state.json (0644: the non-root agent reads it into its host report).
+# Before the service runs (very early boot) the kernel default kernel.panic = 0 applies, so a crash THAT early leaves
+# the box off — the safe side: a box that cannot reach userspace must not loop.
+import json
+import os
+import sys
+import time
+
+CONF = "/etc/felhom/crash-guard.conf"
+STATE_DIR = "/var/lib/felhom-crash-guard"
+DEFAULTS = {"LIMIT": 3, "WINDOW_MINUTES": 60, "PANIC_SECONDS": 10, "REARM_HOURS": 24}
+
+
+class Env:
+    """Paths and clock; tests replace them."""
+
+    def __init__(self, conf=CONF, state_dir=STATE_DIR, panic_path="/proc/sys/kernel/panic",
+                 uptime_path="/proc/uptime", boot_id_path="/proc/sys/kernel/random/boot_id"):
+        self.conf, self.state_dir = conf, state_dir
+        self.panic_path, self.uptime_path, self.boot_id_path = panic_path, uptime_path, boot_id_path
+
+    def now(self):
+        return time.time()
+
+    def log(self, line):
+        print(line, file=sys.stderr, flush=True)
+        try:
+            import subprocess
+            subprocess.run(["logger", "-t", "felhom-crash-guard", line], timeout=10)
+        except Exception:
+            pass
+
+
+def iso(t):
+    return time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime(t))
+
+
+def parse_iso(s):
+    import calendar
+    return calendar.timegm(time.strptime(s, "%Y-%m-%dT%H:%M:%SZ"))
+
+
+def load_conf(env):
+    c = dict(DEFAULTS)
+    try:
+        for line in open(env.conf):
+            line = line.strip()
+            if not line or line.startswith("#") or "=" not in line:
+                continue
+            k, v = (x.strip() for x in line.split("=", 1))
+            if k in c and v.isdigit() and int(v) >= (1 if k != "PANIC_SECONDS" else 1):
+                c[k] = int(v)
+    except OSError:
+        pass
+    return c
+
+
+def state_path(env):
+    return os.path.join(env.state_dir, "state.json")
+
+
+def marker_path(env):
+    return os.path.join(env.state_dir, "clean-stop")
+
+
+def load_state(env):
+    try:
+        with open(state_path(env)) as f:
+            s = json.load(f)
+        return s if isinstance(s, dict) else None
+    except (OSError, ValueError):
+        return None
+
+
+def save_state(env, s):
+    os.makedirs(env.state_dir, mode=0o755, exist_ok=True)
+    tmp = state_path(env) + ".tmp"
+    with open(tmp, "w") as f:
+        json.dump(s, f, indent=2, sort_keys=True)
+        f.write("\n")
+    os.chmod(tmp, 0o644)
+    os.replace(tmp, state_path(env))
+
+
+def set_panic(env, seconds):
+    with open(env.panic_path, "w") as f:
+        f.write(f"{seconds}\n")
+
+
+def read(path, default=""):
+    try:
+        with open(path) as f:
+            return f.read().strip()
+    except OSError:
+        return default
+
+
+def summarize(s, c, now):
+    window = c["WINDOW_MINUTES"] * 60
+    times = [parse_iso(t) for t in s.get("unclean_boots", [])]
+    after = parse_iso(s["rearmed_at"]) if s.get("rearmed_at") else 0
+    # a re-arm starts a fresh window (or the next unclean boot would trip again at once); the history stays
+    s["unclean_boots_in_window"] = sum(1 for t in times if now - t <= window and t > after)
+    s["unclean_boots_24h"] = sum(1 for t in times if now - t <= 86400)
+    s["config"] = c
+    s["updated_at"] = iso(now)
+
+
+def boot(env):
+    c = load_conf(env)
+    now = env.now()
+    try:
+        up = float(read(env.uptime_path, "0").split()[0])
+    except (ValueError, IndexError):
+        up = 0.0
+    boot_at = now - up
+    prev = load_state(env)
+    first = prev is None
+    s = prev or {"version": 1, "unclean_boots": [], "tripped": False}
+    clean = os.path.exists(marker_path(env))
+    unclean = (not first) and (not clean)
+    try:
+        os.remove(marker_path(env))
+    except OSError:
+        pass
+    # keep 7 days of history (the 24 h figure and the operator's view), drop older
+    s["unclean_boots"] = [t for t in s.get("unclean_boots", []) if now - parse_iso(t) <= 7 * 86400]
+    if unclean:
+        s["unclean_boots"].append(iso(boot_at))
+    s["last_boot_at"] = iso(boot_at)
+    s["last_boot_unclean"] = unclean
+    s["boot_id"] = read(env.boot_id_path, "unknown")
+    summarize(s, c, now)
+    if not s.get("tripped") and s["unclean_boots_in_window"] >= c["LIMIT"] - 1:
+        s["tripped"], s["tripped_at"] = True, iso(now)
+        s["tripped_reason"] = (f"{s['unclean_boots_in_window']} unclean boots within {c['WINDOW_MINUTES']} minutes — "
+                               f"the next crash leaves the box off (limit {c['LIMIT']})")
+        env.log(f"crash-guard: TRIPPED: {s['tripped_reason']}")
+    panic = 0 if s.get("tripped") else c["PANIC_SECONDS"]
+    set_panic(env, panic)
+    s["kernel_panic"] = panic
+    s["armed"] = not s.get("tripped")
+    save_state(env, s)
+    env.log(f"crash-guard: boot first={first} unclean={unclean} in-window={s['unclean_boots_in_window']} "
+            f"tripped={s.get('tripped')} kernel.panic={panic}")
+    return 0
+
+
+def clean_stop(env):
+    os.makedirs(env.state_dir, mode=0o755, exist_ok=True)
+    with open(marker_path(env), "w") as f:
+        f.write(iso(env.now()) + "\n")
+    env.log("crash-guard: clean stop recorded")
+    return 0
+
+
+def rearm(env, by):
+    c = load_conf(env)
+    now = env.now()
+    s = load_state(env) or {"version": 1, "unclean_boots": []}
+    was = bool(s.get("tripped"))
+    s["tripped"] = False
+    s["armed"] = True
+    s["rearmed_at"], s["rearmed_by"] = iso(now), by
+    if was:
+        s["last_trip"] = {"at": s.get("tripped_at"), "reason": s.get("tripped_reason")}
+    s.pop("tripped_at", None)
+    s.pop("tripped_reason", None)
+    summarize(s, c, now)
+    set_panic(env, c["PANIC_SECONDS"])
+    s["kernel_panic"] = c["PANIC_SECONDS"]
+    save_state(env, s)
+    env.log(f"crash-guard: RE-ARMED by {by} (was tripped: {was}); kernel.panic={c['PANIC_SECONDS']}")
+    return 0
+
+
+def check(env):
+    c = load_conf(env)
+    now = env.now()
+    s = load_state(env)
+    if not s:
+        return 0
+    if s.get("tripped"):
+        since = max(parse_iso(s["tripped_at"]), parse_iso(s.get("last_boot_at", s["tripped_at"])))
+        if now - since >= c["REARM_HOURS"] * 3600:
+            return rearm(env, f"timer ({c['REARM_HOURS']} h of normal running)")
+    summarize(s, c, now)
+    save_state(env, s)
+    return 0
+
+
+def main(argv, env=None):
+    env = env or Env()
+    cmd = argv[1] if len(argv) == 2 else ""
+    if cmd == "boot":
+        return boot(env)
+    if cmd == "clean-stop":
+        return clean_stop(env)
+    if cmd == "check":
+        return check(env)
+    if cmd == "rearm":
+        return rearm(env, "operator")
+    if cmd == "status":
+        print(json.dumps(load_state(env), indent=2, sort_keys=True))
+        return 0
+    print("usage: felhom-crash-guard boot|clean-stop|check|rearm|status", file=sys.stderr)
+    return 2
+
+
+if __name__ == "__main__":
+    if os.geteuid() != 0:
+        print("felhom-crash-guard: must run as root", file=sys.stderr)
+        sys.exit(2)
+    sys.exit(main(sys.argv))

configs/felhom-crash-guard-check.service

@@ -0,0 +1,7 @@
+# Hourly: a tripped crash guard re-arms after REARM_HOURS of normal running (felhom-crash-guard check).
+[Unit]
+Description=Felhom crash guard re-arm check
+
+[Service]
+Type=oneshot
+ExecStart=/usr/local/sbin/felhom-crash-guard check

configs/felhom-crash-guard-check.timer

@@ -0,0 +1,9 @@
+[Unit]
+Description=Felhom crash guard re-arm check (hourly)
+
+[Timer]
+OnBootSec=15min
+OnUnitActiveSec=1h
+
+[Install]
+WantedBy=timers.target

configs/felhom-crash-guard.service

@@ -0,0 +1,19 @@
+# felhom-crash-guard — a crashed host restarts by itself, with a limit (`09` decision 88, R-851, `11` §5.9).
+# Starts early at boot (sets kernel.panic for THIS boot); its ExecStop writes the clean-stop marker during an orderly
+# shutdown or reboot. A boot that finds no marker followed a crash, a power cut or a hard reset.
+[Unit]
+Description=Felhom crash guard (restart after a kernel crash, with a limit)
+DefaultDependencies=no
+After=local-fs.target
+Before=sysinit.target shutdown.target
+Conflicts=shutdown.target
+RequiresMountsFor=/var/lib
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/usr/local/sbin/felhom-crash-guard boot
+ExecStop=/usr/local/sbin/felhom-crash-guard clean-stop
+
+[Install]
+WantedBy=sysinit.target

configs/felhom-os-apply

@@ -14,7 +14,13 @@
 # file, including the snapshot.debian.org fallback (decision 79). Nothing here is overridable from the environment.
 #
 # LAYERS (agent v0.141.0): "guest" (the customer LXC, entered with `pct exec`) and "host" (this Proxmox host, run
-# directly). LANE: "fast" only — the slow lane (kernel, Proxmox, Docker) is REFUSED (R3, R14) until `11` §8 steps 5–6.
+# directly). LANE: "fast" for those two. Agent v0.142.0 adds the layer "docker" (the guest's Docker engine set, `11`
+# §5.8), which is the SLOW lane: lane "slow" only, the six Docker packages only, origin "Docker CE" only, and only
+# with an authority this file checks ITSELF (R3): a signed operator job verified with `ssh-keygen -Y verify` against
+# the ROOT-OWNED signers file (TRUST_SIGNERS), bound to this host (TRUST_FILE host_id), unexpired and never replayed;
+# or, for an unsigned ring-0 step, the root-owned TRUST_FILE saying `"ring0_slow_lane": true` (set by hand on the demo
+# boxes only). The agent's own config is NOT trusted for either: the agent can write it. A Docker step also needs
+# `live-restore` ON (R15) — without it every container restarts.
 #
 # Modes (plan field "mode"):
 #   inventory   `apt-get update`, then report what is installed (with origin), what is pending, and health.
@@ -22,6 +28,10 @@
 #               pending Debian / Debian-Security upgrade, for ring 0), check every refusal on an `apt-get -s`
 #               simulation of EXACTLY name=version, install, clean, scan for restart-needed, report as inventory.
 #   health      report health only (the agent polls it after a run).
+#   facts       (v0.142.0) read-only versions for the hub's System page: host Debian, running and next-boot kernel,
+#               held packages, kernel taint, the crash guard; guest Debian, Docker engine, containerd, live-restore.
+#   live-restore-on  (v0.142.0, layer guest) the ONE-TIME step of `09` decision 87: merge `"live-restore": true`
+#               into the guest's /etc/docker/daemon.json and `systemctl reload docker`. NEVER a restart (R-835).
 # Output: log lines on stderr and the journal (tag felhom-os-apply); the LAST stdout line is
 #   OSAPPLY-REPORT <one JSON object>
 # which is what the agent parses. Exit 0 = done; 2 = refused (nothing changed); 3 = failed during install.
@@ -30,6 +40,7 @@
 # package for version comparisons — 272 packages ≈ 4 minutes. Versions are now compared with the HOST's dpkg (the same
 # Debian algorithm), madison/policy run once per pass for all packages, the restart scan runs only after an install,
 # and one wrapper call does the whole pass (no separate inventory call before an apply).
+import calendar
 import json
 import os
 import re
@@ -58,7 +69,29 @@ INSTALL_STATE = "/var/lib/felhom-install/state.json"
 # reboot is needed for them to take effect, and a bad one can stop the box from booting.
 HOST_SLOW_RE = re.compile(r"^(linux-(image|headers|kbuild|modules|base)|proxmox-kernel|proxmox-default-kernel|pve-kernel|"
                           r"pve-firmware|firmware-|grub|shim|systemd-boot|intel-microcode|amd64-microcode|efibootmgr)")
+# restart_needed() leaves out processes whose cgroup line matches (grep basic regex). Host: the LXC guests' own
+# processes (`0::/lxc/<vmid>/...`) -- NOT lxc-start itself, whose cgroup is `0::/lxc.monitor/<vmid>` (measured
+# 2026-10-04 on demo-felhom: the old pattern "lxc" hid lxc-start with 20 deleted maps, so "reboot needed" stayed false
+# after a libc6 update). Pinned by test_restart_skip_patterns_against_real_cgroups.
+RESTART_SKIP_CGROUP = {"guest": "docker", "host": ":/lxc/"}
 HOST_SERVICES = ["pveproxy", "pvedaemon", "pvestatd", "pve-cluster", "felhom-agent"]
+# The Docker engine set (`11` §5.8): the only names the docker layer may touch, from the only origin it may use.
+DOCKER_NAMES = ("containerd.io", "docker-buildx-plugin", "docker-ce", "docker-ce-cli", "docker-ce-rootless-extras",
+                "docker-compose-plugin")
+DOCKER_ORIGIN = "Docker CE"
+# ROOT-OWNED trust anchors (the installer writes them; the demo boxes got them by hand, R-840). Never the agent's config.
+TRUST_FILE = "/etc/felhom/os-trust.json"          # {"host_id": "...", "ring0_slow_lane": false}
+TRUST_SIGNERS = "/etc/felhom/operator-signers"    # ssh allowed_signers: <key_id> namespaces="felhom-op-v1" <key>
+SIG_NAMESPACE = "felhom-op-v1"
+SIGNED_OP = "os_docker_step"
+NONCE_FILE = "/var/lib/felhom-os-apply/nonces.json"
+DAEMON_JSON = "/etc/docker/daemon.json"
+# R-858 (v0.142.1): a Docker engine step restarts dockerd, which RECREATES the socket file. With live-restore the
+# containers keep running — and one that bind-mounts the socket FILE keeps the deleted inode: measured 2026-10-04 on
+# demo-felhom, the controller and traefik were blind to Docker for 1h44m. After a step that installed something, the
+# wrapper restarts exactly the containers that mount one of these paths (never the apps, never the engine).
+DOCKER_SOCKETS = ("/var/run/docker.sock", "/run/docker.sock")
+CRASH_GUARD_STATE = "/var/lib/felhom-crash-guard/state.json"
 
 
 class Refused(Exception):
@@ -98,6 +131,38 @@ class Runner:
         if rc != 0:
             raise Refused("R7", f"could not write {path} in the guest")
 
+    def now(self):
+        return time.time()
+
+    def sleep(self, s):
+        time.sleep(s)
+
+    def verify_sig(self, signers, key_id, namespace, blob, sig):
+        """`ssh-keygen -Y verify` over the EXACT signed bytes. Files in a root-only temp dir; nothing via a shell."""
+        import tempfile
+        with tempfile.TemporaryDirectory(prefix="felhom-os-apply-") as d:
+            sp = os.path.join(d, "sig")
+            with open(sp, "w") as f:
+                f.write(sig)
+            p = subprocess.run(["ssh-keygen", "-Y", "verify", "-f", signers, "-I", key_id, "-n", namespace, "-s", sp],
+                               input=blob, capture_output=True, timeout=30)
+            return p.returncode
+
+    def read_nonces(self):
+        try:
+            with open(NONCE_FILE) as f:
+                d = json.load(f)
+            return d if isinstance(d, dict) else {}
+        except (OSError, ValueError):
+            return {}
+
+    def write_nonces(self, d):
+        os.makedirs(os.path.dirname(NONCE_FILE), mode=0o700, exist_ok=True)
+        tmp = NONCE_FILE + ".tmp"
+        with open(tmp, "w") as f:
+            json.dump(d, f)
+        os.replace(tmp, NONCE_FILE)
+
     def log(self, line):
         print(line, file=sys.stderr, flush=True)
         try:
@@ -138,13 +203,22 @@ class Apply:
 
     def check_plan(self, plan):
         mode = plan.get("mode", "apply")
-        if mode not in ("apply", "inventory", "health"):
+        if mode not in ("apply", "inventory", "health", "facts", "live-restore-on"):
             raise Refused("R11", f"unknown mode {mode!r}")
         layer = plan.get("layer")
-        if layer not in ("guest", "host"):
-            raise Refused("R12", f"layer {layer!r} is not guest or host")
-        if plan.get("lane", "fast") != "fast":
-            raise Refused("R3", "the slow lane is refused in this release")
+        if layer not in ("guest", "host", "docker"):
+            raise Refused("R12", f"layer {layer!r} is not guest, host or docker")
+        lane = plan.get("lane", "fast")
+        if layer == "docker" and lane != "slow":
+            raise Refused("R3", "the Docker engine is the slow lane (`11` §5.8); a fast-lane Docker plan is refused")
+        if layer != "docker" and lane != "fast":
+            raise Refused("R3", f"the {layer} layer has no slow lane in this release (kernel, Proxmox: `11` §8 step 6)")
+        if mode == "facts" and layer != "host":
+            raise Refused("R11", "facts is a host-layer mode (it reads the host and the guest)")
+        if mode == "live-restore-on" and layer != "guest":
+            raise Refused("R11", "live-restore-on is a guest-layer mode")
+        if plan.get("undo") and layer != "docker":
+            raise Refused("R5", "an undo (downgrade) exists only for the Docker layer, inside a signed job")
         vmid = plan.get("vmid")
         if not isinstance(vmid, int) or isinstance(vmid, bool) or vmid <= 0:
             raise Refused("R11", f"vmid must be a positive integer, got {vmid!r}")
@@ -154,15 +228,18 @@ class Apply:
         if plan.get("allow_new"):
             raise Refused("R6", "allow_new is a slow-lane field; the fast lane never adds a package")
         select = plan.get("select", "listed")
-        if select not in ("listed", "pending-fast"):
+        if select not in ("listed", "pending-fast", "pending-docker"):
             raise Refused("R11", f"unknown select {select!r}")
+        if (select == "pending-docker") != (layer == "docker" and select != "listed"):
+            if select == "pending-docker" or layer == "docker":
+                raise Refused("R11", f"select {select!r} does not fit layer {layer!r}")
         pk = plan.get("packages", [])
         if not isinstance(pk, list):
             raise Refused("R11", "packages must be a list")
         if mode == "apply" and select == "listed" and not pk:
             raise Refused("R11", "packages must be a non-empty list in apply mode (select listed)")
-        if select == "pending-fast" and pk:
-            raise Refused("R11", "select pending-fast takes no package list")
+        if select in ("pending-fast", "pending-docker") and pk:
+            raise Refused("R11", f"select {select} takes no package list")
         seen = set()
         for e in pk:
             if not isinstance(e, dict):
@@ -175,6 +252,12 @@ class Apply:
             if n in seen:
                 raise Refused("R11", f"package {n} is named twice")
             seen.add(n)
+            if layer == "docker":
+                if n not in DOCKER_NAMES or o != DOCKER_ORIGIN:
+                    raise Refused("R2", f"{n} ({o!r}) is not one of the six Docker packages from {DOCKER_ORIGIN!r}")
+                continue
+            if n in DOCKER_NAMES:
+                raise Refused("R2", f"{n} is a Docker package — the slow lane (`11` §5.8), never in a {layer} plan")
             if o not in FAST_ORIGINS:
                 raise Refused("R2", f"{n}: origin {o!r} is not Debian / Debian-Security (the fast lane, `11` C3)")
             if layer == "host" and HOST_SLOW_RE.match(n):
@@ -199,6 +282,208 @@ class Apply:
         if mode != "appliance":
             raise Refused("R12", f"this box was installed as {mode!r}, not appliance — its host belongs to its owner")
 
+    def load_trust(self):
+        """The ROOT-OWNED trust record. Absent or agent-writable → no slow-lane authority at all (R3)."""
+        try:
+            st = self.r.stat(TRUST_FILE)
+        except OSError:
+            raise Refused("R3", f"no {TRUST_FILE} — this box has no slow-lane trust anchor")
+        if st.st_uid != 0 or (st.st_mode & 0o022):
+            raise Refused("R3", f"{TRUST_FILE} is not root-owned and root-only-writable — it proves nothing")
+        try:
+            t = json.loads(self.r.read_file(TRUST_FILE))
+        except (OSError, ValueError):
+            raise Refused("R3", f"{TRUST_FILE} is unreadable")
+        if not isinstance(t, dict) or not isinstance(t.get("host_id"), str) or not t["host_id"]:
+            raise Refused("R3", f"{TRUST_FILE} names no host_id")
+        return t
+
+    def verify_signed(self, signed, trust):
+        """R3: an operator-signed os_docker_step, checked HERE (not by the agent): signature against the root-owned
+        signers file, op, host binding, time window, and a root-owned nonce record (no replay)."""
+        import base64
+        if not isinstance(signed, dict) or not isinstance(signed.get("blob_b64"), str) or not isinstance(signed.get("sig"), str):
+            raise Refused("R3", "the signed job is malformed")
+        try:
+            blob = base64.b64decode(signed["blob_b64"], validate=True)
+            op = json.loads(blob)
+        except (ValueError, TypeError):
+            raise Refused("R3", "the signed blob is not base64 JSON")
+        key_id = op.get("key_id", "")
+        if not isinstance(key_id, str) or not re.match(r"^[A-Za-z0-9._-]{1,64}$", key_id):
+            raise Refused("R3", "the signed blob names no plain key_id")
+        try:
+            st = self.r.stat(TRUST_SIGNERS)
+        except OSError:
+            raise Refused("R3", f"no {TRUST_SIGNERS} — no operator key to check a signed job against")
+        if st.st_uid != 0 or (st.st_mode & 0o022):
+            raise Refused("R3", f"{TRUST_SIGNERS} is not root-owned and root-only-writable")
+        rc = self.r.verify_sig(TRUST_SIGNERS, key_id, SIG_NAMESPACE, blob, signed["sig"])
+        if rc != 0:
+            raise Refused("R3", f"the operator signature does not verify (ssh-keygen rc={rc})")
+        if op.get("op") != SIGNED_OP:
+            raise Refused("R3", f"the signed op is {op.get('op')!r}, not {SIGNED_OP}")
+        if (op.get("target") or {}).get("host_id") != trust["host_id"]:
+            raise Refused("R3", "the signed job is for another host")
+        now = self.r.now()
+        try:
+            exp = calendar.timegm(time.strptime(op["expires_at"], "%Y-%m-%dT%H:%M:%SZ"))
+            iss = calendar.timegm(time.strptime(op["issued_at"], "%Y-%m-%dT%H:%M:%SZ"))
+        except (KeyError, ValueError, TypeError):
+            raise Refused("R3", "the signed job has no readable time window")
+        if now > exp or now < iss - 120:
+            raise Refused("R3", "the signed job is expired or not yet valid")
+        nonce = op.get("nonce")
+        if not isinstance(nonce, str) or not nonce:
+            raise Refused("R3", "the signed job has no nonce")
+        seen = self.r.read_nonces()
+        if nonce in seen:
+            raise Refused("R3", "the signed job was already used (replay)")
+        seen[nonce] = exp
+        self.r.write_nonces({k: v for k, v in seen.items() if v > now})
+        return op.get("params") or {}
+
+    def docker_authority(self, plan):
+        """R3 for the docker layer: returns (who, undo). A signed job binds the EXACT package list and the undo flag."""
+        trust = self.load_trust()
+        signed = plan.get("signed")
+        if signed:
+            params = self.verify_signed(signed, trust)
+            want = sorted(f"{e.get('name')}={e.get('version')}" for e in params.get("packages") or [])
+            got = sorted(f"{e['name']}={e['version']}" for e in plan.get("packages", []))
+            if not want or want != got:
+                raise Refused("R3", "the plan's packages are not exactly the signed job's packages")
+            if bool(params.get("undo")) != bool(plan.get("undo")):
+                raise Refused("R3", "the plan's undo flag is not the signed job's")
+            if params.get("vmid") not in (None, self.vmid):
+                raise Refused("R3", "the signed job names another guest")
+            return "signed", bool(plan.get("undo"))
+        if plan.get("undo"):
+            raise Refused("R3", "an undo (downgrade) needs a signed operator job")
+        if trust.get("ring0_slow_lane") is True:
+            return "ring0", False
+        raise Refused("R3", "a Docker step needs a signed operator job (ring 1) or this box's root-owned ring-0 mark")
+
+    def live_restore(self):
+        rc, out, _ = self.g(["docker", "info", "--format", "{{.LiveRestoreEnabled}}"], timeout=60)
+        return out.strip() if rc == 0 and out.strip() in ("true", "false") else "unknown"
+
+    def container_ids(self):
+        rc, out, _ = self.g(["docker", "ps", "-q", "--no-trunc"], timeout=60)
+        return sorted(out.split()) if rc == 0 else None
+
+    def live_restore_on(self):
+        """`09` decision 87: merge live-restore into daemon.json and RELOAD (C5: a reload turns it on, no restart)."""
+        log = self.r.log
+        if self.live_restore() == "true":
+            self.report["live_restore"] = {"result": "already on"}
+            log("os-apply: LIVE-RESTORE already on")
+            return 0
+        rc, cur, _ = self.g(["cat", DAEMON_JSON], timeout=30)
+        try:
+            conf = json.loads(cur) if rc == 0 and cur.strip() else {}
+        except ValueError:
+            raise Refused("R16", f"{DAEMON_JSON} in the guest is not valid JSON — not touched")
+        if not isinstance(conf, dict):
+            raise Refused("R16", f"{DAEMON_JSON} is not a JSON object — not touched")
+        before = self.container_ids()
+        conf["live-restore"] = True
+        self.r.write_file("guest", self.vmid, DAEMON_JSON, json.dumps(conf, indent=2, sort_keys=True) + "\n")
+        rrc, _, rerr = self.g(["systemctl", "reload", "docker"], timeout=120)
+        state = "unknown"
+        for _ in range(10):
+            state = self.live_restore()
+            if state == "true":
+                break
+            self.r.sleep(1)
+        after = self.container_ids()
+        same = before is not None and before == after
+        self.report["live_restore"] = {"result": "on" if state == "true" else "failed", "reload_rc": rrc,
+                                       "containers_before": len(before or []), "same_ids": same}
+        log(f"os-apply: LIVE-RESTORE reload_rc={rrc} state={state} containers={len(before or [])} same-ids={'yes' if same else 'NO'}")
+        if state != "true":
+            # put the old file back (and reload again) — still never a restart
+            self.r.write_file("guest", self.vmid, DAEMON_JSON, cur if rc == 0 else "{}\n")
+            self.g(["systemctl", "reload", "docker"], timeout=120)
+            self.report["failed"] = {"rc": 3, "step": "live-restore", "reason": (rerr or "").strip()[-200:]}
+            return 3
+        return 0
+
+    def kernel_next_boot(self):
+        """Which kernel GRUB boots next, read without root-only files (grubenv + /etc/default/grub + /boot)."""
+        try:
+            dflt = re.search(r'^GRUB_DEFAULT=["\']?([^"\'\n]*)', self.r.read_file("/etc/default/grub"), re.M)
+            dflt = dflt.group(1) if dflt else "0"
+        except OSError:
+            dflt = "0"
+        env = {}
+        try:
+            for l in self.r.read_file("/boot/grub/grubenv").splitlines():
+                if "=" in l and not l.startswith("#"):
+                    k, v = l.split("=", 1)
+                    env[k] = v
+        except OSError:
+            pass
+
+        def ver(entry):
+            m = re.search(r"gnulinux-([0-9][^>\s]*?-pve)-(?:advanced|recovery)", entry)
+            return m.group(1) if m else "unknown"
+        if env.get("next_entry"):
+            return ver(env["next_entry"]), "next_entry (a one-shot GRUB cannot clear on LVM /boot)"
+        if dflt == "saved":
+            return (ver(env["saved_entry"]), "saved default") if env.get("saved_entry") else ("unknown", "saved default unset")
+        if dflt == "0":
+            rc, out, _ = self.r.host(["sh", "-c", "ls /boot/vmlinuz-* 2>/dev/null"], 30)
+            vers = [l.split("vmlinuz-", 1)[1] for l in out.split() if "vmlinuz-" in l]
+            best = None
+            for v in vers:
+                if best is None or self.dpkg_cmp(v, "gt", best):
+                    best = v
+            return (best or "unknown"), "GRUB_DEFAULT=0 (the newest installed)"
+        return "unknown", f"GRUB_DEFAULT={dflt}"
+
+    def facts(self):
+        """Read-only versions for the hub's System page (R-852). A value that cannot be read is "unknown"."""
+        def first(cmd, timeout=30):
+            rc, out, _ = self.r.host(cmd, timeout)
+            v = out.strip().splitlines()[0].strip() if rc == 0 and out.strip() else ""
+            return v or "unknown"
+        h = {"debian": first(["cat", "/etc/debian_version"]), "kernel_running": first(["uname", "-r"])}
+        h["kernel_next_boot"], h["kernel_next_boot_source"] = self.kernel_next_boot()
+        rc, out, _ = self.r.host(["apt-mark", "showhold"], 60)
+        h["held"] = sorted(out.split()) if rc == 0 else None
+        try:
+            t = int(self.r.read_file("/proc/sys/kernel/tainted").strip())
+            h["tainted"], h["oops_this_boot"], h["warn_this_boot"] = t, bool(t & 128), bool(t & 512)
+        except (OSError, ValueError):
+            h["tainted"], h["oops_this_boot"], h["warn_this_boot"] = None, None, None
+        try:
+            h["kernel_panic"] = int(self.r.read_file("/proc/sys/kernel/panic").strip())
+        except (OSError, ValueError):
+            h["kernel_panic"] = None
+        try:
+            h["crash_guard"] = json.loads(self.r.read_file(CRASH_GUARD_STATE))
+        except (OSError, ValueError):
+            h["crash_guard"] = None
+        g = {"debian": "unknown", "docker_engine": "unknown", "containerd": "unknown", "live_restore": "unknown"}
+        try:
+            self.check_guest(self.vmid)
+            running = True
+        except Refused as e:
+            running, g["unknown_reason"] = False, f"{e.code} {e.reason}"
+        if running:
+            script = ('echo "debian=$(cat /etc/debian_version 2>/dev/null)"; '
+                      'echo "engine=$(docker version --format \'{{.Server.Version}}\' 2>/dev/null)"; '
+                      'echo "containerd=$(dpkg-query -W -f \'${Version}\' containerd.io 2>/dev/null)"; '
+                      'echo "live=$(docker info --format \'{{.LiveRestoreEnabled}}\' 2>/dev/null)"')
+            rc, out, _ = self.g(["sh", "-c", script], timeout=60)
+            kv = dict(l.split("=", 1) for l in out.splitlines() if "=" in l)
+            for k, src in (("debian", "debian"), ("docker_engine", "engine"), ("containerd", "containerd")):
+                g[k] = kv.get(src, "").strip() or "unknown"
+            g["live_restore"] = {"true": "on", "false": "off"}.get(kv.get("live", "").strip(), "unknown")
+        self.report["facts"] = {"host": h, "guest": g}
+        return 0
+
     def check_guest(self, vmid):
         if vmid in RESERVED_VMIDS:
             raise Refused("R10", f"vmid {vmid} is a reserved scratch vmid")
@@ -222,7 +507,7 @@ class Apply:
         """Run in the TARGET layer: the guest via pct exec, or the host directly."""
         if self.layer == "host":
             return self.r.host(argv, timeout)
-        return self.r.guest(self.vmid, argv, timeout)
+        return self.r.guest(self.vmid, argv, timeout)  # guest and docker both live in the customer guest
 
     def g(self, argv, timeout=1800):
         """Run in the customer GUEST whatever the layer (its health)."""
@@ -284,21 +569,26 @@ class Apply:
 
     def guest_health(self):
         """The guest's signals: every container's state + health, the controller's own health, the network."""
-        rc, out, _ = self.g(["docker", "ps", "-a", "--format", "{{.Names}}\t{{.State}}\t{{.Status}}"], timeout=60)
+        rc, out, _ = self.g(["docker", "ps", "-a", "--no-trunc", "--format", "{{.Names}}\t{{.State}}\t{{.Status}}\t{{.ID}}"], timeout=60)
         cont = {}
         for l in out.splitlines():
             p = l.split("\t")
-            if len(p) == 3:
+            if len(p) >= 3:
                 h = "healthy" if "(healthy)" in p[2] else "unhealthy" if "(unhealthy)" in p[2] else \
                     "starting" if "(health: starting)" in p[2] else "none"
                 cont[p[0]] = {"state": p[1], "health": h}
+                if len(p) >= 4 and p[3]:
+                    cont[p[0]]["id"] = p[3]
         nrc, _, _ = self.g(["getent", "hosts", "deb.debian.org"], timeout=30)
-        return {"docker_ok": rc == 0, "containers": cont,
+        # R-858: the controller's own health check stayed "healthy" while it could not reach Docker at all — so ask
+        # the consequence directly: can the controller talk to the engine from inside its container?
+        crc, _, _ = self.g(["docker", "exec", "felhom-controller", "docker", "version", "--format", "{{.Server.Version}}"], timeout=60)
+        return {"docker_ok": rc == 0, "containers": cont, "controller_docker_ok": crc == 0,
                 "controller": cont.get("felhom-controller", {}).get("health", "absent"),
                 "network_ok": nrc == 0}
 
     def health(self):
-        if self.layer == "guest":
+        if self.layer in ("guest", "docker"):
             return self.guest_health()
         rc, out, _ = self.r.host(["systemctl", "is-active"] + HOST_SERVICES, 30)
         states = out.split()
@@ -310,7 +600,7 @@ class Apply:
     def restart_needed(self):
         """Processes still mapping deleted files, OUTSIDE containers (C11). Guest: outside docker; host: outside the
         LXC guests (the host's /proc shows guest processes too)."""
-        skip = "docker" if self.layer == "guest" else "lxc"
+        skip = RESTART_SKIP_CGROUP["host" if self.layer == "host" else "guest"]
         script = ('for p in /proc/[0-9]*; do grep -q "(deleted)" $p/maps 2>/dev/null || continue; '
                   'grep -q "%s" $p/cgroup 2>/dev/null && continue; echo "${p#/proc/} $(cat $p/comm 2>/dev/null)"; done' % skip)
         rc, out, _ = self.x(["sh", "-c", script], timeout=120)
@@ -368,16 +658,28 @@ class Apply:
         plan = self.load_plan()
         self.mode, self.layer, self.vmid, self.select = self.check_plan(plan)
         self.report.update(mode=self.mode, layer=self.layer, release_id=plan.get("release_id"), vmid=self.vmid)
+        if self.mode == "facts":
+            return self.facts()
         if self.layer == "host":
             self.check_appliance()
         self.check_guest(self.vmid)
         log = self.r.log
+        if self.mode == "live-restore-on":
+            return self.live_restore_on()
+        self.who, self.allow_downgrade = ("fast", False)
+        if self.layer == "docker" and self.mode == "apply":
+            self.who, self.allow_downgrade = self.docker_authority(plan)
+            if self.live_restore() != "true":
+                raise Refused("R15", "live-restore is not ON in the guest — a Docker step would restart every container")
+            self.report["authority"] = self.who
+            self.report["undo"] = self.allow_downgrade
         if self.mode == "health":
             self.report["health"] = self.health()
             return 0
         log(f"os-apply: START release={plan.get('release_id')} layer={self.layer}" +
-            (f":{self.vmid}" if self.layer == "guest" else "") +
-            f" lane=fast mode={self.mode} select={self.select} packages={len(plan.get('packages', []))}")
+            (f":{self.vmid}" if self.layer != "host" else "") +
+            f" lane={plan.get('lane', 'fast')} mode={self.mode} select={self.select} packages={len(plan.get('packages', []))}" +
+            (f" authority={self.who}{' UNDO' if self.allow_downgrade else ''}" if self.layer == "docker" else ""))
         if self.apt_lock_held():
             raise Refused("R9", f"another apt/dpkg holds the lock on the {self.layer}")
         self.report["health_before"] = self.health()
@@ -392,6 +694,16 @@ class Apply:
             if rc:
                 return rc
         self.report.update(self.inventory(installed_after))
+        if "reboot_needed" not in self.report:
+            # EVERY layer is scanned on EVERY pass: a reboot (host) or a restart (guest) must CLEAR "restart needed",
+            # or the fleet view keeps a stale date (R-849, v0.142.0; the host since v0.141.1). One pct exec, ~1 s.
+            # Pinned by test_every_layer_scans_every_pass.
+            self.report["restart_needed"], self.report["reboot_needed"] = self.restart_needed()
+            self.report["docker_restart_needed"] = any(p in ("dockerd", "containerd") for p in self.report["restart_needed"])
+        if self.layer == "docker":
+            rc_v, out_v, _ = self.g(["docker", "version", "--format", "{{.Server.Version}}"], timeout=60)
+            self.report["docker_engine"] = out_v.strip() if rc_v == 0 and out_v.strip() else "unknown"
+        self.report["reboot_scanned"] = "reboot_needed" in self.report
         self.report["health_after"] = self.health()
         return 0
 
@@ -424,9 +736,44 @@ class Apply:
             out.append({"name": p["name"], "version": p["to"], "origin": "Debian-Security" if "Debian-Security" in o else "Debian"})
         return out
 
+    def restart_socket_users(self):
+        """R-858: restart ONLY the containers that bind-mount the Docker socket, so they attach to the new one."""
+        rc, out, _ = self.g(["docker", "ps", "-q", "--no-trunc"], timeout=60)
+        users = []
+        for cid in out.split():
+            irc, iout, _ = self.g(["docker", "inspect", "-f", "{{.Name}}|{{range .Mounts}}{{.Destination}};{{end}}", cid], timeout=60)
+            if irc != 0 or "|" not in iout:
+                continue
+            name, mounts = iout.strip().split("|", 1)
+            if any(m in DOCKER_SOCKETS for m in mounts.split(";")):
+                users.append(name.lstrip("/"))
+        users.sort()
+        if users:
+            rrc, _, rerr = self.g(["docker", "restart"] + users, timeout=300)
+            self.r.log(f"os-apply: SOCKET-USERS restarted={','.join(users)} rc={rrc} (R-858: they held the old docker socket)")
+        return users
+
+    def pending_docker(self):
+        """Ring 0 (select pending-docker): the newest pending version of each INSTALLED Docker package, Docker origin."""
+        rc, pend, remv, _ = self.simulate(["dist-upgrade"])
+        return [{"name": p["name"], "version": p["to"], "origin": DOCKER_ORIGIN} for p in pend
+                if p["from"] is not None and p["name"] in DOCKER_NAMES and self.origin_name(p["origin"]) == {DOCKER_ORIGIN}]
+
+    def origin_ok(self, origin):
+        o = self.origin_name(origin)
+        if self.layer == "docker":
+            return o == {DOCKER_ORIGIN}
+        return bool(o & set(FAST_ORIGINS))
+
     def apply(self, plan):
         log = self.r.log
-        packages = plan["packages"] if self.select == "listed" else self.pending_fast()
+        if self.select == "listed":
+            packages = plan["packages"]
+        elif self.select == "pending-docker":
+            packages = self.pending_docker()
+        else:
+            packages = self.pending_fast()
+        cmp_op = "ne" if self.allow_downgrade else "gt"
         inst = self.installed()
         upgrade, already, notinst = [], 0, 0
         for e in packages:
@@ -434,7 +781,7 @@ class Apply:
             if n not in inst:
                 notinst += 1
                 continue
-            if not self.dpkg_cmp(v, "gt", inst[n]):
+            if not self.dpkg_cmp(v, cmp_op, inst[n]):
                 already += 1
                 continue
             upgrade.append((n, v))
@@ -462,7 +809,8 @@ class Apply:
                 self.report["upgraded"] = []
                 log("os-apply: DONE rc=0 seconds=0 upgraded=0 (nothing to do)")
                 return 0, inst
-            args = ["install", "--only-upgrade", "--no-install-recommends"] + [f"{n}={v}" for n, v in upgrade]
+            args = ["install", "--only-upgrade", "--no-install-recommends"] + \
+                (["--allow-downgrades"] if self.allow_downgrade else []) + [f"{n}={v}" for n, v in upgrade]
             rc, sim, remv, text = self.simulate(args)
             if rc != 0:
                 tail = text.strip().splitlines()[-1] if text.strip() else ""
@@ -477,10 +825,10 @@ class Apply:
                     raise Refused("R6", f"the plan would touch {p['name']}, which is not in the plan")
                 if p["to"] != want[p["name"]]:
                     raise Refused("R6", f"{p['name']} would go to {p['to']}, not the approved {want[p['name']]}")
-                if not self.dpkg_cmp(p["to"], "gt", p["from"]):
+                if not self.allow_downgrade and not self.dpkg_cmp(p["to"], "gt", p["from"]):
                     raise Refused("R5", f"{p['name']} would be downgraded {p['from']} -> {p['to']}")
-                if not self.origin_name(p["origin"]) & set(FAST_ORIGINS):
-                    raise Refused("R2", f"{p['name']} would come from {p['origin']}, not Debian")
+                if not self.origin_ok(p["origin"]):
+                    raise Refused("R2", f"{p['name']} would come from {p['origin']}, not the {self.layer} layer's origin")
                 if self.layer == "host" and HOST_SLOW_RE.match(p["name"]):
                     raise Refused("R14", f"{p['name']} is a kernel / boot / firmware package — the host's slow lane")
             need = self.download_bytes(args)
@@ -514,7 +862,9 @@ class Apply:
                 return 3, None
             self.report["upgraded"] = [{"name": n, "version": v} for n, v in upgrade]
             self.report["seconds"] = round(secs, 1)
-            procs, reboot = self.restart_needed()  # only after an install (R-845)
+            if self.layer == "docker":
+                self.report["socket_restarted"] = self.restart_socket_users()
+            procs, reboot = self.restart_needed()
             self.report["restart_needed"] = procs
             self.report["docker_restart_needed"] = any(p in ("dockerd", "containerd") for p in procs)
             self.report["reboot_needed"] = reboot

configs/test_felhom_crash_guard.py

@@ -0,0 +1,143 @@
+#!/usr/bin/python3
+"""Tests for felhom-crash-guard (`11` §5.9). Temp dirs only; nothing real is touched. Red-proof seam: CRASHGUARD_UNDER_TEST."""
+import importlib.machinery
+import importlib.util
+import json
+import os
+import pathlib
+import tempfile
+import unittest
+
+HERE = pathlib.Path(__file__).resolve().parent
+_loader = importlib.machinery.SourceFileLoader("crashguard", os.environ.get("CRASHGUARD_UNDER_TEST", str(HERE / "felhom-crash-guard")))
+_spec = importlib.util.spec_from_loader("crashguard", _loader)
+cg = importlib.util.module_from_spec(_spec)
+_loader.exec_module(cg)
+
+T0 = 1791115200.0  # 2026-10-04T12:00:00Z
+
+
+class FakeEnv(cg.Env):
+    def __init__(self, d):
+        super().__init__(conf=os.path.join(d, "conf"), state_dir=os.path.join(d, "state"),
+                         panic_path=os.path.join(d, "panic"), uptime_path=os.path.join(d, "uptime"),
+                         boot_id_path=os.path.join(d, "bootid"))
+        self.t = T0
+        self.logs = []
+        open(self.panic_path, "w").write("0\n")
+        open(self.uptime_path, "w").write("20.00 10.00\n")
+
+    def now(self):
+        return self.t
+
+    def log(self, line):
+        self.logs.append(line)
+
+    def panic(self):
+        return int(open(self.panic_path).read())
+
+    def state(self):
+        return json.load(open(os.path.join(self.state_dir, "state.json")))
+
+
+class Guard(unittest.TestCase):
+    def setUp(self):
+        self.d = tempfile.TemporaryDirectory()
+        self.e = FakeEnv(self.d.name)
+
+    def tearDown(self):
+        self.d.cleanup()
+
+    def crash_boot(self, minutes_later):
+        self.e.t += minutes_later * 60
+        cg.main(["x", "boot"], self.e)  # no clean-stop before it: an unclean stop
+
+    def clean_reboot(self, minutes_later):
+        cg.main(["x", "clean-stop"], self.e)
+        self.e.t += minutes_later * 60
+        cg.main(["x", "boot"], self.e)
+
+    def test_first_boot_is_not_a_crash_and_arms(self):
+        cg.main(["x", "boot"], self.e)
+        s = self.e.state()
+        self.assertFalse(s["last_boot_unclean"])
+        self.assertEqual(self.e.panic(), 10)
+        self.assertTrue(s["armed"])
+
+    def test_clean_reboots_never_count(self):
+        cg.main(["x", "boot"], self.e)
+        for _ in range(5):
+            self.clean_reboot(1)
+        s = self.e.state()
+        self.assertEqual(s["unclean_boots_in_window"], 0)
+        self.assertEqual(self.e.panic(), 10)
+
+    def test_third_crash_in_an_hour_leaves_the_box_off(self):
+        # operator's words: "if it crashes 3 times within one hour, it stays off" — after crash 2 the guard trips,
+        # so crash 3 (kernel.panic = 0) does not restart the box.
+        cg.main(["x", "boot"], self.e)
+        self.crash_boot(5)
+        self.assertEqual(self.e.panic(), 10, "one crash: still restarts")
+        self.crash_boot(5)
+        s = self.e.state()
+        self.assertTrue(s["tripped"], s)
+        self.assertEqual(self.e.panic(), 0, "after the 2nd crash boot the 3rd crash must leave the box off")
+        self.assertIn("2 unclean boots within 60 minutes", s["tripped_reason"])
+
+    def test_crashes_spread_over_more_than_the_window_do_not_trip(self):
+        cg.main(["x", "boot"], self.e)
+        self.crash_boot(5)
+        self.crash_boot(61)
+        self.assertFalse(self.e.state()["tripped"])
+        self.assertEqual(self.e.panic(), 10)
+
+    def test_tripped_stays_tripped_across_boots(self):
+        cg.main(["x", "boot"], self.e)
+        self.crash_boot(5)
+        self.crash_boot(5)
+        self.clean_reboot(30)  # the operator switched it on; even a clean boot keeps the trip
+        self.assertTrue(self.e.state()["tripped"])
+        self.assertEqual(self.e.panic(), 0)
+
+    def test_rearms_after_24h_of_normal_running(self):
+        cg.main(["x", "boot"], self.e)
+        self.crash_boot(5)
+        self.crash_boot(5)
+        self.e.t += 23 * 3600
+        cg.main(["x", "check"], self.e)
+        self.assertTrue(self.e.state()["tripped"], "not before 24 h")
+        self.e.t += 3600
+        cg.main(["x", "check"], self.e)
+        s = self.e.state()
+        self.assertFalse(s["tripped"])
+        self.assertEqual(self.e.panic(), 10)
+        self.assertIn("timer", s["rearmed_by"])
+
+    def test_operator_rearm_starts_a_fresh_window(self):
+        cg.main(["x", "boot"], self.e)
+        self.crash_boot(5)
+        self.crash_boot(5)
+        self.e.t += 60
+        cg.main(["x", "rearm"], self.e)
+        s = self.e.state()
+        self.assertFalse(s["tripped"])
+        self.assertEqual(s["rearmed_by"], "operator")
+        self.assertEqual(s["unclean_boots_24h"], 2, "the history stays")
+        self.crash_boot(5)
+        self.assertFalse(self.e.state()["tripped"], "one crash after a re-arm must not trip at once")
+
+    def test_config_numbers_are_read(self):
+        open(self.e.conf, "w").write("LIMIT=2\nPANIC_SECONDS=30\n")
+        cg.main(["x", "boot"], self.e)
+        self.assertEqual(self.e.panic(), 30)
+        self.crash_boot(1)
+        self.assertTrue(self.e.state()["tripped"], "LIMIT=2: the first crash boot trips")
+
+    def test_state_is_world_readable_for_the_agent(self):
+        cg.main(["x", "boot"], self.e)
+        mode = os.stat(os.path.join(self.e.state_dir, "state.json")).st_mode & 0o777
+        self.assertEqual(mode, 0o644)
+
+
+if __name__ == "__main__":
+    unittest.main()

configs/test_felhom_os_apply.py

@@ -64,6 +64,35 @@ class Fake:
         self.services = {}
         self.files[osapply.INSTALL_STATE] = json.dumps({"mode": "appliance"})
         self.stats[osapply.INSTALL_STATE] = St(mode=statmod.S_IFREG | 0o644, uid=0)
+        # Docker / trust / facts state (v0.142.0)
+        self.live_restore = "true"
+        self.ids = ["aaa111", "bbb222"]
+        self.engine = "29.7.2"
+        self.daemon_json = '{"log-driver": "json-file"}'
+        self.reload_enables = True
+        self.sig_rc = 0
+        self.nonces = {}
+        self.clock = 1791115200.0  # 2026-10-04T12:00:00Z
+        self.files[osapply.TRUST_FILE] = json.dumps({"host_id": "demo-hp-bb76ea", "ring0_slow_lane": False})
+        self.stats[osapply.TRUST_FILE] = St(mode=statmod.S_IFREG | 0o644, uid=0)
+        self.files[osapply.TRUST_SIGNERS] = 'felhom-op-1 namespaces="felhom-op-v1" ssh-ed25519 AAAA\n'
+        self.stats[osapply.TRUST_SIGNERS] = St(mode=statmod.S_IFREG | 0o644, uid=0)
+
+    def now(self):
+        return self.clock
+
+    def sleep(self, s):
+        pass
+
+    def verify_sig(self, signers, key_id, ns, blob, sig):
+        self.verified = (signers, key_id, ns, blob, sig)
+        return self.sig_rc
+
+    def read_nonces(self):
+        return dict(self.nonces)
+
+    def write_nonces(self, d):
+        self.nonces = dict(d)
 
     # Runner interface
     def read_file(self, p):
@@ -151,11 +180,46 @@ class Fake:
                 return 0, getattr(self, "install_out", "Setting up libc6 ...\n"), ""
         if cmd == "df":
             return 0, f"Avail\n{self.free}\n", ""
+        if cmd == "docker" and a[1] == "info":
+            return 0, self.live_restore + "\n", ""
+        if cmd == "docker" and a[1] == "version":
+            return 0, self.engine + "\n", ""
+        if cmd == "docker" and a[1:3] == ["ps", "-q"]:
+            return 0, "".join(i + "\n" for i in self.ids), ""
+        if cmd == "docker" and a[1] == "inspect":
+            mounts = {"aaa111": "/felhom-controller|/var/run/docker.sock;/app/data;", "bbb222": "/app|/data;"}
+            return 0, mounts.get(a[-1], "/other|;") + "\n", ""
+        if cmd == "docker" and a[1] == "restart":
+            self.restarted_containers = a[2:]
+            return 0, "", ""
+        if cmd == "docker" and a[1] == "exec":
+            return (1, "", "Cannot connect to the Docker daemon") if getattr(self, "controller_blind", False) else (0, self.engine + "\n", "")
         if cmd == "docker":
-            return 0, "felhom-controller\trunning\tUp 1 hour (healthy)\napp\trunning\tUp 1 hour (healthy)\n", ""
+            ids = self.ids + ["x"] * 2
+            return 0, f"felhom-controller\trunning\tUp 1 hour (healthy)\t{ids[0]}\napp\trunning\tUp 1 hour (healthy)\t{ids[1]}\n", ""
+        if cmd == "cat" and a[1] == osapply.DAEMON_JSON:
+            return (0, self.daemon_json, "") if self.daemon_json is not None else (1, "", "No such file")
+        if cmd == "cat" and a[1] == "/etc/debian_version":
+            return 0, "13.7\n", ""
+        if cmd == "uname":
+            return 0, "7.0.14-20-pve\n", ""
+        if cmd == "apt-mark":
+            return 0, getattr(self, "held", ""), ""
+        if cmd == "systemctl" and a[1] == "reload":
+            self.reloads = getattr(self, "reloads", 0) + 1
+            if self.reload_enables and '"live-restore": true' in self.written.get(osapply.DAEMON_JSON, ""):
+                self.live_restore = "true"
+            return 0, "", ""
+        if cmd == "systemctl" and a[1] == "restart":
+            self.restarted = True
+            return 0, "", ""
         if cmd == "getent":
             return 0, "1.2.3.4 deb.debian.org\n", ""
         if cmd == "sh":
+            if "vmlinuz" in a[2]:
+                return 0, "/boot/vmlinuz-7.0.2-6-pve\n/boot/vmlinuz-7.0.14-20-pve\n", ""
+            if "engine=" in a[2]:
+                return 0, f"debian=13.7\nengine={self.engine}\ncontainerd=2.3.3-1~debian.13~trixie\nlive={self.live_restore}\n", ""
             if "os-release" in a[2]:
                 return 0, "trixie\n", ""
             if "(deleted)" in a[2]:
@@ -180,7 +244,7 @@ class Fake:
                 n, v = x.split("=", 1)
                 if v not in self.avail(n):
                     return 100, "", f"E: Version '{v}' for '{n}' was not found"
-                origin = SEC if n == "openssl" else DEB
+                origin = "Docker CE:trixie" if n in osapply.DOCKER_NAMES else SEC if n == "openssl" else DEB
                 out += f"Inst {n} [{self.installed[n]}] ({v} {origin} [amd64])\n"
         out += "".join(l + "\n" for l in self.extra_sim)
         return 0, out, ""
@@ -226,7 +290,6 @@ class Happy(unittest.TestCase):
         self.assertEqual(rc, 0, rep)
         self.assertEqual(f.installed["libc6"], "2.41-12+deb13u3")
         self.assertIn("installed", rep)
-        self.assertNotIn("restart_needed", rep, "the restart scan runs only after an install (R-845)")
 
     def test_health_mode(self):
         f = Fake()
@@ -551,6 +614,23 @@ class HostLayer(unittest.TestCase):
         rc, rep = run(f)
         self.assertTrue(rep["reboot_needed"], rep)
 
+    def test_every_layer_scans_every_pass(self):
+        # R-849 (v0.142.0): host AND guest are scanned on every pass, so a reboot / restart clears the flag.
+        for layer in ("host", "guest"):
+            f = Fake()
+            f.plan["layer"] = layer
+            f.plan["mode"] = "inventory"
+            f.restart_out = "2101 lxc-start\n" if layer == "host" else "1 systemd\n"
+            rc, rep = run(f)
+            self.assertEqual(rc, 0, rep)
+            self.assertTrue(rep["reboot_scanned"] and rep["reboot_needed"], (layer, rep))
+            f = Fake()
+            f.plan["layer"] = layer
+            f.plan["mode"] = "inventory"
+            f.restart_out = ""
+            rc, rep = run(f)
+            self.assertTrue(rep["reboot_scanned"] and rep["reboot_needed"] is False, (layer, rep))
+
     def test_no_reboot_for_ordinary_daemons(self):
         f = Fake()
         f.plan["layer"] = "host"
@@ -586,5 +666,299 @@ class Failure(unittest.TestCase):
         self.assertTrue(any(l.startswith("os-apply: FAILED rc=100 step=install") for l in f.logs))
 
 
+
+class RestartSkipPattern(unittest.TestCase):
+    """The cgroup filter runs as `grep -q PATTERN /proc/<pid>/cgroup`; check it with grep itself against the cgroup
+    lines measured on demo-felhom 2026-10-04."""
+
+    def grep(self, pattern, line):
+        return subprocess.run(["grep", "-q", pattern], input=line + "\n", text=True).returncode == 0
+
+    def test_restart_skip_patterns_against_real_cgroups(self):
+        host = osapply.RESTART_SKIP_CGROUP["host"]
+        self.assertTrue(self.grep(host, "0::/lxc/9201/ns/system.slice/docker.service"), "a guest process must be skipped")
+        self.assertFalse(self.grep(host, "0::/lxc.monitor/9201"), "lxc-start must NOT be skipped (it runs the guest)")
+        self.assertFalse(self.grep(host, "0::/system.slice/pve-cluster.service"), "a host daemon must NOT be skipped")
+        guest = osapply.RESTART_SKIP_CGROUP["guest"]
+        self.assertTrue(self.grep(guest, "0::/system.slice/docker-0123abcd.scope"))
+        self.assertFalse(self.grep(guest, "0::/system.slice/cron.service"))
+
+
+DOCKER_SET = [{"name": "docker-ce", "version": "5:29.8.2-1~debian.13~trixie", "origin": "Docker CE"},
+              {"name": "containerd.io", "version": "2.3.6-1~debian.13~trixie", "origin": "Docker CE"}]
+
+
+def docker_fake(signed=None, undo=False, ring0=False):
+    f = Fake()
+    f.installed.update({"docker-ce": "5:29.7.2-1~debian.13~trixie", "containerd.io": "2.3.3-1~debian.13~trixie"})
+    f.live["docker-ce"] = {"5:29.8.2-1~debian.13~trixie", "5:29.7.2-1~debian.13~trixie"}
+    f.live["containerd.io"] = {"2.3.6-1~debian.13~trixie", "2.3.3-1~debian.13~trixie"}
+    f.plan = {"release_id": "os-docker-t1", "layer": "docker", "lane": "slow", "vmid": 9201, "mode": "apply",
+              "packages": [dict(p) for p in DOCKER_SET]}
+    if undo:
+        f.plan["undo"] = True
+    if ring0:
+        f.files[osapply.TRUST_FILE] = json.dumps({"host_id": "demo-hp-bb76ea", "ring0_slow_lane": True})
+    if signed is not None:
+        f.plan["signed"] = signed
+    return f
+
+
+def signed_job(packages=DOCKER_SET, host="demo-hp-bb76ea", op="os_docker_step", undo=False, nonce="n1",
+               issued="2026-10-04T11:50:00Z", expires="2026-10-04T12:30:00Z"):
+    import base64
+    params = {"packages": packages, "undo": undo}
+    blob = json.dumps({"expires_at": expires, "issued_at": issued, "key_id": "felhom-op-1", "nonce": nonce, "op": op,
+                       "params": params, "target": {"guest_id": "", "host_id": host}}, sort_keys=True).encode()
+    return {"blob_b64": base64.b64encode(blob).decode(), "sig": "-----BEGIN SSH SIGNATURE-----\nx\n-----END SSH SIGNATURE-----\n"}
+
+
+class DockerLane(unittest.TestCase):
+    """`11` §5.8, agent v0.142.0. Each test names the refusal it pins; the red-proof file mutates each one."""
+
+    def refused(self, f, code):
+        rc, rep = run(f)
+        self.assertEqual(rc, 2, rep)
+        self.assertEqual(rep["refused"]["code"], code, rep)
+        self.assertEqual(f.installed.get("docker-ce", "5:29.7.2-1~debian.13~trixie"), "5:29.7.2-1~debian.13~trixie")
+        return rep
+
+    def test_docker_package_in_a_fast_plan_is_refused(self):
+        f = Fake()
+        f.plan["packages"].append({"name": "docker-ce", "version": "5:29.8.2-1~debian.13~trixie", "origin": "Debian"})
+        self.refused(f, "R2")
+
+    def test_docker_layer_in_the_fast_lane_is_refused(self):
+        f = docker_fake(ring0=True)
+        f.plan["lane"] = "fast"
+        self.refused(f, "R3")
+
+    def test_no_authority_is_refused(self):
+        self.refused(docker_fake(), "R3")
+
+    def test_ring0_mark_allows_pending_docker(self):
+        f = docker_fake(ring0=True)
+        f.plan["select"], f.plan["packages"] = "pending-docker", []
+        f.pending_sim = ["Inst docker-ce [5:29.7.2-1~debian.13~trixie] (5:29.8.2-1~debian.13~trixie Docker CE:trixie [amd64])",
+                         "Inst containerd.io [2.3.3-1~debian.13~trixie] (2.3.6-1~debian.13~trixie Docker CE:trixie [amd64])",
+                         "Inst bash [5.2.37-2+b9] (5.2.37-2+b10 Debian:13.7/stable [amd64])"]
+        rc, rep = run(f)
+        self.assertEqual(rc, 0, rep)
+        self.assertEqual(rep["authority"], "ring0")
+        self.assertEqual(f.installed["docker-ce"], "5:29.8.2-1~debian.13~trixie")
+        self.assertEqual(f.installed["bash"], "5.2.37-2+b9", "a Debian package must not ride a Docker step")
+        self.assertFalse(getattr(f, "restarted", False), "never a docker restart")
+
+    def test_signed_job_applies_exactly_its_packages(self):
+        f = docker_fake(signed=signed_job())
+        rc, rep = run(f)
+        self.assertEqual(rc, 0, rep)
+        self.assertEqual(rep["authority"], "signed")
+        self.assertEqual(f.installed["containerd.io"], "2.3.6-1~debian.13~trixie")
+        self.assertEqual(f.verified[0], osapply.TRUST_SIGNERS, "the ROOT-OWNED signers file, not the agent's config")
+        self.assertIn("n1", f.nonces)
+
+    def test_bad_signature_is_refused(self):
+        f = docker_fake(signed=signed_job())
+        f.sig_rc = 255
+        self.refused(f, "R3")
+        self.assertEqual(f.nonces, {}, "a bad signature must not burn a nonce")
+
+    def test_signed_job_for_another_host_is_refused(self):
+        self.refused(docker_fake(signed=signed_job(host="demo-felhom-8363b5")), "R3")
+
+    def test_signed_job_other_op_is_refused(self):
+        self.refused(docker_fake(signed=signed_job(op="agent_update")), "R3")
+
+    def test_expired_signed_job_is_refused(self):
+        self.refused(docker_fake(signed=signed_job(expires="2026-10-04T11:55:00Z")), "R3")
+
+    def test_replayed_signed_job_is_refused(self):
+        f = docker_fake(signed=signed_job())
+        f.nonces = {"n1": f.clock + 600}
+        self.refused(f, "R3")
+
+    def test_plan_must_equal_the_signed_packages(self):
+        f = docker_fake(signed=signed_job(packages=DOCKER_SET[:1]))
+        self.refused(f, "R3")
+
+    def test_agent_writable_trust_file_is_refused(self):
+        f = docker_fake(ring0=True)
+        f.stats[osapply.TRUST_FILE] = St(mode=statmod.S_IFREG | 0o644, uid=999)
+        self.refused(f, "R3")
+
+    def test_live_restore_off_is_refused(self):
+        f = docker_fake(signed=signed_job())
+        f.live_restore = "false"
+        self.refused(f, "R15")
+
+    def test_undo_needs_a_signed_job(self):
+        self.refused(docker_fake(undo=True, ring0=True), "R3")
+
+    def test_signed_undo_downgrades(self):
+        old = [{"name": "docker-ce", "version": "5:29.7.2-1~debian.13~trixie", "origin": "Docker CE"}]
+        f = docker_fake(signed=signed_job(packages=old, undo=True), undo=True)
+        f.plan["packages"] = [dict(p) for p in old]
+        f.installed["docker-ce"] = "5:29.8.2-1~debian.13~trixie"
+        rc, rep = run(f)
+        self.assertEqual(rc, 0, rep)
+        self.assertEqual(f.installed["docker-ce"], "5:29.7.2-1~debian.13~trixie")
+        self.assertTrue(rep["undo"])
+
+    def test_unsigned_downgrade_is_refused(self):
+        f = docker_fake(ring0=True)
+        f.plan["packages"] = [{"name": "docker-ce", "version": "5:29.6.0-1~debian.13~trixie", "origin": "Docker CE"}]
+        f.live["docker-ce"].add("5:29.6.0-1~debian.13~trixie")
+        rc, rep = run(f)
+        self.assertEqual(rep["plan"]["upgrade"], 0, "an older version on an unsigned step is 'already', never installed")
+
+    def test_step_restarts_only_the_socket_users(self):
+        # R-858: after an engine step, ONLY the container that mounts the docker socket is restarted (here the controller)
+        f = docker_fake(signed=signed_job())
+        rc, rep = run(f)
+        self.assertEqual(rc, 0, rep)
+        self.assertEqual(f.restarted_containers, ["felhom-controller"])
+        self.assertEqual(rep["socket_restarted"], ["felhom-controller"])
+
+    def test_no_install_restarts_nothing(self):
+        f = docker_fake(signed=signed_job())
+        f.installed.update({"docker-ce": "5:29.8.2-1~debian.13~trixie", "containerd.io": "2.3.6-1~debian.13~trixie"})
+        rc, rep = run(f)
+        self.assertFalse(hasattr(f, "restarted_containers"), "nothing installed -> no container restart")
+
+    def test_health_says_when_the_controller_cannot_reach_docker(self):
+        f = docker_fake(signed=signed_job())
+        f.controller_blind = True
+        rc, rep = run(f)
+        self.assertFalse(rep["health_after"]["controller_docker_ok"])
+
+    def test_health_carries_container_ids(self):
+        f = docker_fake(signed=signed_job())
+        rc, rep = run(f)
+        self.assertEqual(rep["health_after"]["containers"]["app"]["id"], "bbb222")
+        self.assertEqual(rep["docker_engine"], "29.7.2")
+
+
+class LiveRestore(unittest.TestCase):
+    def lr(self):
+        f = Fake()
+        f.plan = {"release_id": "lr", "layer": "guest", "lane": "fast", "vmid": 9201, "mode": "live-restore-on", "packages": []}
+        f.live_restore = "false"
+        return f
+
+    def test_turns_it_on_with_a_reload_never_a_restart(self):
+        f = self.lr()
+        rc, rep = run(f)
+        self.assertEqual(rc, 0, rep)
+        self.assertEqual(json.loads(f.written[osapply.DAEMON_JSON]), {"log-driver": "json-file", "live-restore": True})
+        self.assertEqual(f.reloads, 1)
+        self.assertFalse(getattr(f, "restarted", False))
+        self.assertEqual(rep["live_restore"]["result"], "on")
+        self.assertTrue(rep["live_restore"]["same_ids"])
+
+    def test_already_on_writes_nothing(self):
+        f = self.lr()
+        f.live_restore = "true"
+        rc, rep = run(f)
+        self.assertEqual(rc, 0)
+        self.assertNotIn(osapply.DAEMON_JSON, f.written)
+
+    def test_invalid_daemon_json_is_left_alone(self):
+        f = self.lr()
+        f.daemon_json = "{not json"
+        rc, rep = run(f)
+        self.assertEqual(rep["refused"]["code"], "R16")
+        self.assertNotIn(osapply.DAEMON_JSON, f.written)
+
+    def test_reload_that_does_not_enable_puts_the_file_back(self):
+        f = self.lr()
+        f.reload_enables = False
+        rc, rep = run(f)
+        self.assertEqual(rc, 3, rep)
+        self.assertEqual(f.written[osapply.DAEMON_JSON], '{"log-driver": "json-file"}')
+        self.assertFalse(getattr(f, "restarted", False))
+
+
+class Facts(unittest.TestCase):
+    def facts(self, f=None):
+        f = f or Fake()
+        f.plan = {"release_id": "facts", "layer": "host", "lane": "fast", "vmid": 9201, "mode": "facts", "packages": []}
+        rc, rep = run(f)
+        self.assertEqual(rc, 0, rep)
+        return f, rep["facts"]
+
+    def test_reads_host_and_guest(self):
+        f = Fake()
+        f.files["/proc/sys/kernel/tainted"] = "4225\n"  # 4096 + 128 (D: oops) + 1
+        f.files["/proc/sys/kernel/panic"] = "10\n"
+        f.held = "tzdata\n"
+        f.files["/etc/default/grub"] = "GRUB_DEFAULT=saved\n"
+        f.files["/boot/grub/grubenv"] = "# GRUB Environment Block\nsaved_entry=gnulinux-advanced-x>gnulinux-7.0.14-20-pve-advanced-x\n"
+        _, fa = self.facts(f)
+        h, g = fa["host"], fa["guest"]
+        self.assertEqual((h["debian"], h["kernel_running"], h["kernel_next_boot"]), ("13.7", "7.0.14-20-pve", "7.0.14-20-pve"))
+        self.assertEqual(h["held"], ["tzdata"])
+        self.assertTrue(h["oops_this_boot"])
+        self.assertEqual(h["kernel_panic"], 10)
+        self.assertEqual((g["debian"], g["docker_engine"], g["live_restore"]), ("13.7", "29.7.2", "on"))
+        self.assertEqual(g["containerd"], "2.3.3-1~debian.13~trixie")
+
+    def test_next_entry_wins_and_default_zero_is_the_newest(self):
+        f = Fake()
+        f.files["/etc/default/grub"] = "GRUB_DEFAULT=saved\n"
+        f.files["/boot/grub/grubenv"] = "saved_entry=gnulinux-advanced-x>gnulinux-7.0.2-6-pve-advanced-x\nnext_entry=gnulinux-advanced-x>gnulinux-7.0.14-20-pve-advanced-x\n"
+        _, fa = self.facts(f)
+        self.assertEqual(fa["host"]["kernel_next_boot"], "7.0.14-20-pve")
+        self.assertIn("next_entry", fa["host"]["kernel_next_boot_source"])
+        f = Fake()
+        f.files["/etc/default/grub"] = "GRUB_DEFAULT=0\n"
+        _, fa = self.facts(f)
+        self.assertEqual(fa["host"]["kernel_next_boot"], "7.0.14-20-pve", "dpkg order, not string order (7.0.2 < 7.0.14)")
+
+    def test_stopped_guest_is_unknown_never_guessed(self):
+        f = Fake()
+        f.status = "status: stopped"
+        _, fa = self.facts(f)
+        self.assertEqual(fa["guest"]["docker_engine"], "unknown")
+        self.assertIn("R10", fa["guest"]["unknown_reason"])
+        self.assertEqual(fa["host"]["tainted"], None, "unreadable -> None, not 0")
+
+
+class RealSignatureCheck(unittest.TestCase):
+    """The REAL Runner.verify_sig with the real ssh-keygen and a throwaway key, in the installer's allowed_signers form
+    (`<key_id> namespaces="felhom-op-v1" <type> <b64> <comment>`). Nothing leaves the temp dir."""
+
+    def setUp(self):
+        import shutil
+        if not shutil.which("ssh-keygen"):
+            self.skipTest("ssh-keygen not available")
+        import tempfile
+        self.d = tempfile.mkdtemp()
+        self.key = os.path.join(self.d, "k")
+        subprocess.run(["ssh-keygen", "-q", "-t", "ed25519", "-N", "", "-C", "felhom-op-1", "-f", self.key], check=True)
+        pub = open(self.key + ".pub").read().strip()
+        self.signers = os.path.join(self.d, "signers")
+        open(self.signers, "w").write(f'felhom-op-1 namespaces="felhom-op-v1" {pub}\n')
+
+    def sign(self, blob, ns="felhom-op-v1"):
+        bp = os.path.join(self.d, "blob")
+        open(bp, "wb").write(blob)
+        if os.path.exists(bp + ".sig"):
+            os.remove(bp + ".sig")  # ssh-keygen -Y sign asks before overwriting (it would wait on stdin)
+        subprocess.run(["ssh-keygen", "-q", "-Y", "sign", "-f", self.key, "-n", ns, bp], check=True, stdin=subprocess.DEVNULL, timeout=30)
+        return open(bp + ".sig").read()
+
+    def test_good_signature_verifies(self):
+        blob = b'{"op":"os_docker_step"}'
+        self.assertEqual(osapply.Runner().verify_sig(self.signers, "felhom-op-1", "felhom-op-v1", blob, self.sign(blob)), 0)
+
+    def test_changed_blob_wrong_namespace_or_wrong_principal_fail(self):
+        blob = b'{"op":"os_docker_step"}'
+        sig = self.sign(blob)
+        r = osapply.Runner()
+        self.assertNotEqual(r.verify_sig(self.signers, "felhom-op-1", "felhom-op-v1", blob + b" ", sig), 0)
+        self.assertNotEqual(r.verify_sig(self.signers, "someone-else", "felhom-op-v1", blob, sig), 0)
+        self.assertNotEqual(r.verify_sig(self.signers, "felhom-op-1", "felhom-op-v1", blob, self.sign(blob, ns="other-ns")), 0)
+
 if __name__ == "__main__":
     unittest.main()

internal/hub/collect.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
+	"encoding/json"
 	"fmt"
 	"io"
 	"log/slog"
 	"os"
+	"strings"
 	"time"
 
 	"gitea.dooplex.hu/admin/felhom-agent/internal/capability"
@@ -108,6 +110,7 @@ type Collector struct {
 	selfUpdate   SelfUpdateReporter                            // D1: agent self-update pending status (nil → false)
 	mgmtPlane    MgmtPlaneReporter                             // G1: management-plane health (nil → stanza omitted)
 	oob          OOBReporter                                   // H1: operator-access health (nil → stanza omitted)
+	system       SystemReporter                                // R-852: the box versions (nil → API fields only)
 	backupTarget func() ConfiguredBackupTarget                 // R-109: primary backup tier id (nil → recipe records unknown)
 	hostID       string
 	agentVersion string
@@ -248,6 +251,41 @@ type OOBReporter interface {
 }
 
 // SetOOBReporter wires the operator-access health source (H1; nil-safe → stanza omitted).
+// SystemReporter reads the box's versions (R-852): the customer guest's vmid and the wrapper's raw facts.
+type SystemReporter interface {
+	SystemFacts(ctx context.Context) (vmid int, facts json.RawMessage, err error)
+}
+
+// SetSystemReporter wires the facts read (agent v0.142.0). Without it the stanza carries the Proxmox API fields only.
+func (c *Collector) SetSystemReporter(r SystemReporter) *Collector {
+	c.system = r
+	return c
+}
+
+func unknownIfEmpty(s string) string {
+	if strings.TrimSpace(s) == "" {
+		return "unknown"
+	}
+	return s
+}
+
+// systemInfo builds the `system` stanza. Never fatal: a failed facts read is FactsError, the API fields stay.
+func (c *Collector) systemInfo(ctx context.Context, ns proxmox.NodeStatus) *SystemInfo {
+	si := &SystemInfo{PVEVersion: unknownIfEmpty(ns.PVEVersion), KernelVersion: unknownIfEmpty(ns.KVersion),
+		ReadAt: c.now().Format(time.RFC3339)}
+	if c.system == nil {
+		si.FactsError = "no facts reader wired"
+		return si
+	}
+	vmid, f, err := c.system.SystemFacts(ctx)
+	si.VMID, si.Facts = vmid, f
+	if err != nil {
+		si.FactsError = err.Error()
+		c.logger.Debug("hub: system facts unavailable", "err", err)
+	}
+	return si
+}
+
 func (c *Collector) SetOOBReporter(o OOBReporter) *Collector {
 	c.oob = o
 	return c
@@ -284,6 +322,7 @@ func (c *Collector) Collect(ctx context.Context) (*HostReport, error) {
 		Capabilities:    c.capabilities(ctx),
 		LeafFingerprint: c.leafFP,
 		Addresses:       c.collectAddresses(),
+		System:          c.systemInfo(ctx, ns),
 	}
 	// DR recipe host-half — derived from the just-collected guest/storage/PBS facts (no new reads).
 	// Secret-free by construction (identifiers/intents/sizes/coordinates only).

internal/hub/report.go

@@ -89,6 +89,12 @@ type HostReport struct {
 	// hub-schema change and are absent when the reporter is not wired.
 	MgmtPlane *MgmtPlaneStatus `json:"mgmt_plane,omitempty"`
 
+	// System is the box's versions for the hub's System page (agent v0.142.0, R-852, `09` decision 89): Proxmox and the
+	// running kernel from the Proxmox API, and the wrapper's read-only facts (host Debian, next-boot kernel, held
+	// packages, taint, the crash guard; guest Debian, Docker engine, containerd, live-restore). A value nobody could
+	// read is "unknown", never empty and never guessed. The hub v0.132.0 consumes it (hosts + System pages).
+	System *SystemInfo `json:"system,omitempty"`
+
 	// PBSDR is the PBS-DR-tier bridge status stanza (slice 2). Present only when the pbsdr
 	// consumer is wired. `consumed_failed` is the LOUD persistent state: the one-time token
 	// secret was consumed but the apply failed afterwards — the secret is burned, the bridge
@@ -241,6 +247,16 @@ type WireguardStatus struct {
 	AssignedIP        string `json:"assigned_ip,omitempty"` // from the marker, e.g. "10.77.0.2/32"
 }
 
+// SystemInfo is the `system` stanza (see HostReport.System).
+type SystemInfo struct {
+	PVEVersion    string          `json:"pve_version"`    // GET /nodes/{node}/status pveversion
+	KernelVersion string          `json:"kernel_version"` // GET /nodes/{node}/status kversion
+	VMID          int             `json:"vmid,omitempty"` // the customer guest the facts read
+	Facts         json.RawMessage `json:"facts,omitempty"`
+	FactsError    string          `json:"facts_error,omitempty"`
+	ReadAt        string          `json:"read_at"`
+}
+
 // HostMetrics is the host block, sourced from proxmox NodeStatus.
 type HostMetrics struct {
 	Node             string   `json:"node"`

internal/osupdate/dockerjob.go

@@ -0,0 +1,88 @@
+package osupdate
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+
+	"gitea.dooplex.hu/admin/felhom-agent/internal/signedjobs"
+)
+
+// OpDockerStep is the signed op class of a Docker engine step (`11` §5.8): a ring-1 box takes an approved engine set,
+// and every box takes an UNDO, only through it. CC may sign it until the first paying customer (R-530 ruling).
+const OpDockerStep = "os_docker_step"
+
+// DockerStepParams are the signed params. The wrapper compares Packages and Undo with the plan byte-for-byte.
+type DockerStepParams struct {
+	ReleaseID string    `json:"release_id"`
+	Packages  []Package `json:"packages"`
+	Undo      bool      `json:"undo"`
+	VMID      int       `json:"vmid,omitempty"`
+}
+
+// DockerStepExecutor runs a verified os_docker_step (signedjobs.Executor). Guest finds the box's customer guest when
+// the params name none; Gate (optional) takes the host-wide heavy-op gate so a step never runs beside a backup.
+type DockerStepExecutor struct {
+	Leg   *Leg
+	Guest func(ctx context.Context) (int, error)
+	Gate  func(ctx context.Context) (release func(), err error)
+}
+
+// Execute implements signedjobs.Executor.
+func (e DockerStepExecutor) Execute(ctx context.Context, op string, params json.RawMessage) error {
+	if op != OpDockerStep {
+		return signedjobs.ErrNoExecutor
+	}
+	so, ok := signedjobs.SignedOpFrom(ctx)
+	if !ok {
+		return fmt.Errorf("os_docker_step: no signed envelope in the context — the wrapper could not verify it")
+	}
+	var p DockerStepParams
+	if err := json.Unmarshal(params, &p); err != nil || len(p.Packages) == 0 {
+		return fmt.Errorf("os_docker_step: params must name the engine set: %v", err)
+	}
+	vmid := p.VMID
+	if vmid == 0 {
+		if e.Guest == nil {
+			return fmt.Errorf("os_docker_step: no vmid and no guest finder")
+		}
+		v, err := e.Guest(ctx)
+		if err != nil {
+			return fmt.Errorf("os_docker_step: find the customer guest: %w", err)
+		}
+		vmid = v
+	}
+	if e.Gate != nil {
+		release, err := e.Gate(ctx)
+		if err != nil {
+			return fmt.Errorf("os_docker_step: heavy-op gate busy (a backup or restore-test runs): %w", err)
+		}
+		defer release()
+	}
+	rep := e.Leg.RunDockerSigned(ctx, vmid, p, so.Blob, string(so.Sig))
+	switch rep.Outcome {
+	case "applied", "nothing":
+		if rep.Healthy {
+			return nil
+		}
+	}
+	return fmt.Errorf("os_docker_step: %s (%s) %s", rep.Outcome, rep.HealthReason, string(rep.Refused))
+}
+
+// RunDockerSigned is one signed Docker step (ring 1 or an undo): live-restore first (decision 87, a no-op when on),
+// then the docker layer with the signed envelope, which the wrapper verifies itself.
+func (l *Leg) RunDockerSigned(ctx context.Context, vmid int, p DockerStepParams, blob []byte, sig string) Report {
+	runID := l.now().UTC().Format("20060102T150405Z")
+	lg := l.log().With("run", runID, "vmid", vmid, "trigger", "signed", "release", p.ReleaseID, "undo", p.Undo)
+	if err := l.EnsureLiveRestore(ctx, runID, vmid); err != nil {
+		return l.finish(ctx, lg, Report{RunID: runID, Layer: LayerDocker, Trigger: "signed", Ring: l.Block().Ring, VMID: vmid,
+			Mode: "apply", ReleaseID: p.ReleaseID, Outcome: "failed", HealthReason: "live-restore could not be turned on: " + err.Error()})
+	}
+	rid := p.ReleaseID
+	if rid == "" {
+		rid = "signed-" + runID
+	}
+	return l.runLayer(ctx, runID, LayerDocker, vmid, "signed", l.Block(), dockerOpts{releaseID: rid, packages: p.Packages,
+		undo: p.Undo, signed: map[string]string{"blob_b64": base64.StdEncoding.EncodeToString(blob), "sig": sig}})
+}

internal/osupdate/dockerjob_test.go

@@ -0,0 +1,49 @@
+package osupdate
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"testing"
+
+	"gitea.dooplex.hu/admin/felhom-agent/internal/hub"
+	"gitea.dooplex.hu/admin/felhom-agent/internal/reconcile"
+	"gitea.dooplex.hu/admin/felhom-agent/internal/signedjobs"
+)
+
+// The executor hands the RAW signed bytes to the wrapper (which verifies them itself) and the exact signed package
+// list. Red-proof: drop the `signed` field from the docker plan in runLayer and the plan check fails.
+func TestDockerStepExecutor_PassesTheSignedEnvelope(t *testing.T) {
+	w := &fakeWrapper{t: t, applyRep: map[string]WrapperReport{LayerDocker: {
+		Upgraded: []Package{{Name: "docker-ce", Version: "5:29.8.2-1~debian.13~trixie"}}, DockerEngine: "29.8.2", Authority: "signed"}}}
+	l, h := newLeg(t, w, &hub.WireOSUpdate{Ring: 1, Enabled: true})
+	e := DockerStepExecutor{Leg: l, Guest: func(context.Context) (int, error) { return 9201, nil }}
+	params, _ := json.Marshal(DockerStepParams{ReleaseID: "os-docker-1", Packages: []Package{{Name: "docker-ce", Version: "5:29.8.2-1~debian.13~trixie", Origin: "Docker CE"}}})
+	ctx := signedjobs.WithSignedOp(context.Background(), &reconcile.SignedOp{Blob: []byte(`{"op":"os_docker_step"}`), Sig: []byte("SIG")})
+	if err := e.Execute(ctx, OpDockerStep, params); err != nil {
+		t.Fatal(err)
+	}
+	dp := w.plans[len(w.plans)-1]
+	sg, _ := dp["signed"].(map[string]any)
+	if dp["layer"] != "docker" || dp["lane"] != "slow" || dp["release_id"] != "os-docker-1" || sg == nil ||
+		sg["blob_b64"] != base64.StdEncoding.EncodeToString([]byte(`{"op":"os_docker_step"}`)) || sg["sig"] != "SIG" {
+		t.Fatalf("docker plan = %v", dp)
+	}
+	if calls(w) != "guest:live-restore-on,docker:apply" || len(h.reports) != 1 || h.reports[0].Trigger != "signed" {
+		t.Fatalf("calls=%s reports=%+v", calls(w), h.reports)
+	}
+}
+
+func TestDockerStepExecutor_RefusesWithoutEnvelopeAndPassesOtherOps(t *testing.T) {
+	w := &fakeWrapper{t: t}
+	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 1, Enabled: true})
+	e := DockerStepExecutor{Leg: l, Guest: func(context.Context) (int, error) { return 9201, nil }}
+	if err := e.Execute(context.Background(), "agent_update", nil); !errors.Is(err, signedjobs.ErrNoExecutor) {
+		t.Fatalf("another op must pass through the chain: %v", err)
+	}
+	params, _ := json.Marshal(DockerStepParams{Packages: []Package{{Name: "docker-ce", Version: "1"}}})
+	if err := e.Execute(context.Background(), OpDockerStep, params); err == nil || len(w.plans) != 0 {
+		t.Fatalf("no envelope must refuse before any wrapper call: err=%v calls=%s", err, calls(w))
+	}
+}

internal/osupdate/leg.go

@@ -1,5 +1,7 @@
-// Package osupdate is the agent's OS-update leg (`11-os-updates.md` §8 steps 2–3): the customer GUEST's Debian fast
-// lane (agent v0.140.0) and, after it in the same pass, the HOST's (agent v0.141.0).
+// Package osupdate is the agent's OS-update leg (`11-os-updates.md` §8 steps 2–3, §5.8): the customer GUEST's Debian
+// fast lane (agent v0.140.0), after it in the same pass the HOST's (agent v0.141.0), and then — ring 0 only — the
+// guest's DOCKER engine set, the slow lane (agent v0.142.0; a ring-1 box takes a Docker step only inside a signed
+// operator job, DockerStepExecutor). It also reads the box's versions for the hub's System page (Facts, R-852).
 //
 // It runs right after the night's successful whole-guest backup, while the backup goroutine still holds the host-wide
 // heavy-op gate (so it never overlaps a backup or a restore-test, `11` C10), at most once per night. All root work is
@@ -35,10 +37,15 @@ const DefaultPlanDir = "/var/lib/felhom-agent/os"
 
 // Layers.
 const (
-	LayerGuest = "guest"
-	LayerHost  = "host"
+	LayerGuest  = "guest"
+	LayerHost   = "host"
+	LayerDocker = "docker" // the guest's Docker engine set — slow lane (`11` §5.8)
 )
 
+// DockerNames are the six packages of the Docker engine set (the wrapper's DOCKER_NAMES).
+var DockerNames = map[string]bool{"containerd.io": true, "docker-buildx-plugin": true, "docker-ce": true,
+	"docker-ce-cli": true, "docker-ce-rootless-extras": true, "docker-compose-plugin": true}
+
 // Package is one name=version with its origin.
 type Package struct {
 	Name    string `json:"name"`
@@ -58,6 +65,7 @@ type Pending struct {
 type Container struct {
 	State  string `json:"state"`
 	Health string `json:"health"` // healthy | unhealthy | starting | none
+	ID     string `json:"id,omitempty"`
 }
 
 // Health is one health reading. Guest layer: DockerOK..Containers. Host layer: HostServices, GuestRunning and the
@@ -67,6 +75,9 @@ type Health struct {
 	NetworkOK    bool                 `json:"network_ok"`
 	Controller   string               `json:"controller"`
 	Containers   map[string]Container `json:"containers"`
+	// ControllerDockerOK: the controller reaches the engine from INSIDE its container (R-858, wrapper ≥ v0.142.1;
+	// nil from an older wrapper = not checked). Its own health check stayed "healthy" while it was blind.
+	ControllerDockerOK *bool `json:"controller_docker_ok,omitempty"`
 	HostServices map[string]string    `json:"host_services,omitempty"`
 	GuestRunning *bool                `json:"guest_running,omitempty"`
 	Guest        *Health              `json:"guest,omitempty"`
@@ -84,10 +95,16 @@ type WrapperReport struct {
 	RestartNeeded       []string        `json:"restart_needed"`
 	DockerRestartNeeded bool            `json:"docker_restart_needed"`
 	RebootNeeded        bool            `json:"reboot_needed"`
+	RebootScanned       bool            `json:"reboot_scanned"`
 	HealthBefore        *Health         `json:"health_before"`
 	HealthAfter         *Health         `json:"health_after"`
 	Health              *Health         `json:"health"`
 	PassSeconds         float64         `json:"pass_seconds"`
+	DockerEngine        string          `json:"docker_engine"`
+	Authority           string          `json:"authority"`
+	Undo                bool            `json:"undo"`
+	LiveRestore         json.RawMessage `json:"live_restore"`
+	Facts               json.RawMessage `json:"facts"`
 }
 
 func (w WrapperReport) refused() bool { return len(w.Refused) > 0 && string(w.Refused) != "null" }
@@ -112,8 +129,12 @@ type Report struct {
 	RestartNeeded       []string        `json:"restart_needed,omitempty"`
 	DockerRestartNeeded bool            `json:"docker_restart_needed,omitempty"`
 	RebootNeeded        bool            `json:"reboot_needed,omitempty"`
+	RebootScanned       bool            `json:"reboot_scanned,omitempty"` // the pass looked (host: every pass) — a false RebootNeeded then means "not needed"
 	Refused             json.RawMessage `json:"refused,omitempty"`
 	PassSeconds         float64         `json:"pass_seconds,omitempty"`
+	DockerEngine        string          `json:"docker_engine,omitempty"` // docker layer: the engine after the step
+	Authority           string          `json:"authority,omitempty"`     // docker layer: ring0 | signed
+	Undo                bool            `json:"undo,omitempty"`          // docker layer: a signed undo (downgrade)
 }
 
 // Reporter posts a report to the hub (*hub.Client).
@@ -222,6 +243,9 @@ func HealthVerdict(before, after *Health) (bool, string) {
 	if after.Controller != "healthy" {
 		return false, "the controller is " + after.Controller
 	}
+	if after.ControllerDockerOK != nil && !*after.ControllerDockerOK {
+		return false, "the controller cannot reach Docker (it holds an old socket — R-858)"
+	}
 	if before == nil {
 		return true, ""
 	}
@@ -282,6 +306,49 @@ func HostHealthVerdict(before, after *Health, tunnel string) (bool, string) {
 	return true, ""
 }
 
+// EngineOf is the engine version `docker version` prints for a docker-ce package version: "5:29.8.2-1~debian.13~trixie"
+// → "29.8.2" (no epoch, no Debian revision).
+func EngineOf(pkgVersion string) string {
+	v := pkgVersion
+	if i := strings.Index(v, ":"); i >= 0 {
+		v = v[i+1:]
+	}
+	if i := strings.Index(v, "-"); i >= 0 {
+		v = v[:i]
+	}
+	return v
+}
+
+// DockerHealthVerdict is THE Docker-step health rule (`11` §5.8; pinned by TestDockerHealthVerdict): the guest rule,
+// plus every container running at the start still runs as the SAME container (same id — a changed id means the
+// household's apps restarted, which `live-restore` exists to prevent), plus the engine now reports the version the step
+// installed (wantEngine "" = no engine change expected).
+func DockerHealthVerdict(before, after *Health, wantEngine, gotEngine string) (bool, string) {
+	if ok, why := HealthVerdict(before, after); !ok {
+		return false, why
+	}
+	if before != nil {
+		names := make([]string, 0, len(before.Containers))
+		for n := range before.Containers {
+			names = append(names, n)
+		}
+		sort.Strings(names)
+		for _, n := range names {
+			b := before.Containers[n]
+			if b.State != "running" || b.ID == "" {
+				continue
+			}
+			if a := after.Containers[n]; a.ID != b.ID {
+				return false, n + " is a new container (id changed) — the engine step restarted it"
+			}
+		}
+	}
+	if wantEngine != "" && gotEngine != wantEngine {
+		return false, "the engine is " + gotEngine + ", not " + wantEngine
+	}
+	return true, ""
+}
+
 // call writes the plan and runs the wrapper once.
 func (l *Leg) call(ctx context.Context, runID string, plan map[string]any) (WrapperReport, error) {
 	dir := l.PlanDir
@@ -318,9 +385,85 @@ func (l *Leg) call(ctx context.Context, runID string, plan map[string]any) (Wrap
 	return rep, nil // a refusal / failure is IN the report (exit 2 / 3), not an error here
 }
 
-// Run is one pass: the guest layer, then (on an appliance, after a good guest step) the host layer. Returns both
-// reports (host empty when skipped). trigger is "night" or "debug".
-func (l *Leg) Run(ctx context.Context, vmid int, trigger string) (guest Report, host Report) {
+// Pass is one leg's reports; an empty Layer means the step did not run.
+type Pass struct {
+	Guest, Host, Docker Report
+}
+
+// Run is one pass: the guest layer, then (on an appliance, after a good guest step) the host layer, then (ring 0
+// only, after good earlier steps) the Docker engine set. trigger is "night" or "debug".
+func (l *Leg) Run(ctx context.Context, vmid int, trigger string) Pass {
+	g, h := l.runFast(ctx, vmid, trigger)
+	p := Pass{Guest: g, Host: h}
+	if g.Outcome == "skipped" {
+		return p
+	}
+	blk := l.Block()
+	okStep := func(r Report) bool {
+		return (r.Outcome == "applied" || r.Outcome == "nothing" || r.Outcome == "inventory") && r.Healthy
+	}
+	lg := l.log().With("run", g.RunID, "vmid", vmid, "trigger", trigger)
+	switch {
+	case blk.Ring != 0 || !blk.Enabled:
+		lg.Info("osupdate: docker step skipped — ring 1 takes an engine set only inside a signed operator job (`11` §5.8)", "ring", blk.Ring, "enabled", blk.Enabled)
+	case !okStep(g) || (h.Layer != "" && !okStep(h)):
+		lg.Warn("osupdate: docker step skipped — an earlier step did not end healthy")
+	default:
+		if err := l.EnsureLiveRestore(ctx, g.RunID, vmid); err != nil {
+			p.Docker = l.finish(ctx, lg, Report{RunID: g.RunID, Layer: LayerDocker, Trigger: trigger, Ring: 0, VMID: vmid,
+				Mode: "apply", Outcome: "failed", HealthReason: "live-restore could not be turned on: " + err.Error()})
+			return p
+		}
+		p.Docker = l.runLayer(ctx, g.RunID, LayerDocker, vmid, trigger, blk, dockerOpts{})
+	}
+	return p
+}
+
+// dockerOpts is a signed Docker step (DockerStepExecutor); the zero value is ring 0's unsigned "pending-docker".
+type dockerOpts struct {
+	releaseID string
+	packages  []Package
+	undo      bool
+	signed    map[string]string // blob_b64, sig — the wrapper verifies them ITSELF
+}
+
+// EnsureLiveRestore is the ONE-TIME step of `09` decision 87: the wrapper merges `"live-restore": true` into the guest's
+// daemon.json and RELOADS docker (never a restart, R-835). A no-op when it is already on.
+func (l *Leg) EnsureLiveRestore(ctx context.Context, runID string, vmid int) error {
+	wr, err := l.call(ctx, runID, map[string]any{"release_id": "live-restore", "layer": LayerGuest, "lane": "fast",
+		"vmid": vmid, "mode": "live-restore-on", "packages": []Package{}})
+	if err != nil {
+		return err
+	}
+	if wr.refused() {
+		return fmt.Errorf("refused: %s", wr.Refused)
+	}
+	if wr.failed() {
+		return fmt.Errorf("failed: %s", wr.Failed)
+	}
+	l.log().Info("osupdate: live-restore", "vmid", vmid, "result", string(wr.LiveRestore))
+	return nil
+}
+
+// Facts reads the box's versions through the wrapper's read-only facts mode (R-852): host Debian, kernels, held
+// packages, taint, the crash guard; guest Debian, Docker engine, containerd, live-restore. Raw JSON, the wrapper's shape.
+func (l *Leg) Facts(ctx context.Context, vmid int) (json.RawMessage, error) {
+	wr, err := l.call(ctx, "facts"+l.now().UTC().Format("150405"), map[string]any{"release_id": "facts", "layer": LayerHost,
+		"lane": "fast", "vmid": vmid, "mode": "facts", "packages": []Package{}})
+	if err != nil {
+		return nil, err
+	}
+	if wr.refused() {
+		return nil, fmt.Errorf("facts refused: %s", wr.Refused)
+	}
+	if len(wr.Facts) == 0 {
+		return nil, fmt.Errorf("facts: the wrapper returned none (an older wrapper?)")
+	}
+	return wr.Facts, nil
+}
+
+// runFast is the guest + host fast lane (agent v0.141.x behaviour).
+func (l *Leg) runFast(ctx context.Context, vmid int, trigger string) (guest Report, host Report) {
 	runID := l.now().UTC().Format("20060102T150405Z")
 	lg := l.log().With("run", runID, "vmid", vmid, "trigger", trigger)
 	if trigger == "night" && l.StatePath != "" {
@@ -336,7 +479,7 @@ func (l *Leg) Run(ctx context.Context, vmid int, trigger string) (guest Report,
 		}
 	}
 	blk := l.Block()
-	guest = l.runLayer(ctx, runID, LayerGuest, vmid, trigger, blk)
+	guest = l.runLayer(ctx, runID, LayerGuest, vmid, trigger, blk, dockerOpts{})
 	if trigger == "night" && l.StatePath != "" {
 		_ = os.WriteFile(l.StatePath, []byte(l.now().UTC().Format(time.RFC3339)), 0o600)
 	}
@@ -346,20 +489,27 @@ func (l *Leg) Run(ctx context.Context, vmid int, trigger string) (guest Report,
 	case !(guest.Outcome == "applied" || guest.Outcome == "nothing" || guest.Outcome == "inventory") || !guest.Healthy:
 		lg.Warn("osupdate: host step skipped — the guest step did not end healthy", "guest_outcome", guest.Outcome, "reason", guest.HealthReason)
 	default:
-		host = l.runLayer(ctx, runID, LayerHost, vmid, trigger, blk)
+		host = l.runLayer(ctx, runID, LayerHost, vmid, trigger, blk, dockerOpts{})
 	}
 	return guest, host
 }
 
-func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigger string, blk hub.WireOSUpdate) Report {
+func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigger string, blk hub.WireOSUpdate, do dockerOpts) Report {
 	rel := hub.WireOSRelease{ID: "ring0-" + runID}
 	var wire *hub.WireOSRelease
-	if layer == LayerGuest {
+	switch layer {
+	case LayerGuest:
 		wire = blk.Release
-	} else {
+	case LayerHost:
 		wire = blk.HostRelease
 	}
-	if blk.Ring == 1 {
+	lane := "fast"
+	if layer == LayerDocker {
+		lane = "slow"
+		if do.signed != nil {
+			rel = hub.WireOSRelease{ID: do.releaseID}
+		}
+	} else if blk.Ring == 1 {
 		rel = hub.WireOSRelease{}
 		if wire != nil {
 			rel = *wire
@@ -369,13 +519,23 @@ func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigg
 	lg := l.log().With("run", runID, "layer", layer, "vmid", vmid, "ring", blk.Ring, "trigger", trigger)
 	lg.Info("osupdate: START", "enabled", blk.Enabled, "release", rel.ID)
 
-	plan := map[string]any{"release_id": rel.ID, "layer": layer, "lane": "fast", "vmid": vmid, "snapshot": rel.Snapshot,
+	plan := map[string]any{"release_id": rel.ID, "layer": layer, "lane": lane, "vmid": vmid, "snapshot": rel.Snapshot,
 		"packages": []Package{}, "mode": "apply", "select": "listed"}
 	if rel.ID == "" {
 		plan["release_id"] = "none"
 	}
 	planned := map[string]bool{}
 	switch {
+	case layer == LayerDocker && do.signed != nil:
+		plan["packages"], plan["signed"] = do.packages, do.signed
+		if do.undo {
+			plan["undo"] = true
+		}
+		for _, p := range do.packages {
+			planned[p.Name] = true
+		}
+	case layer == LayerDocker:
+		plan["select"] = "pending-docker" // ring 0: the wrapper checks the box's ROOT-OWNED ring-0 mark itself
 	case !blk.Enabled:
 		plan["mode"] = "inventory"
 		lg.Info("osupdate: switched OFF for this box — reporting only")
@@ -404,6 +564,7 @@ func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigg
 		rep.Outcome, rep.Refused = "failed", wr.Failed
 	}
 	rep.Upgraded, rep.PassSeconds = wr.Upgraded, wr.PassSeconds
+	rep.DockerEngine, rep.Authority, rep.Undo = wr.DockerEngine, wr.Authority, wr.Undo
 	if rep.Outcome == "" {
 		switch {
 		case rep.Mode == "inventory" && !blk.Enabled:
@@ -421,7 +582,16 @@ func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigg
 	}
 	// Health: compare with the start of the pass; give restarted services time (only after an install).
 	cur := wr.HealthAfter
+	wantEngine := ""
+	for _, u := range wr.Upgraded {
+		if u.Name == "docker-ce" {
+			wantEngine = EngineOf(u.Version)
+		}
+	}
 	verdict := func(h *Health) (bool, string) {
+		if layer == LayerDocker {
+			return DockerHealthVerdict(wr.HealthBefore, h, wantEngine, wr.DockerEngine)
+		}
 		if layer == LayerHost {
 			t := hub.TunnelUnknown
 			if l.Tunnel != nil {
@@ -447,7 +617,7 @@ func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigg
 				break
 			}
 			l.sleep(ctx, poll)
-			hp := map[string]any{"release_id": plan["release_id"], "layer": layer, "lane": "fast", "vmid": vmid, "mode": "health", "packages": []Package{}}
+			hp := map[string]any{"release_id": plan["release_id"], "layer": layer, "lane": lane, "vmid": vmid, "mode": "health", "packages": []Package{}}
 			hr, herr := l.call(ctx, runID, hp)
 			if herr == nil && hr.Health != nil {
 				cur = hr.Health
@@ -461,10 +631,37 @@ func (l *Leg) runLayer(ctx context.Context, runID, layer string, vmid int, trigg
 	}
 	rep.Installed, rep.Pending = wr.Installed, wr.Pending
 	rep.RestartNeeded, rep.DockerRestartNeeded, rep.RebootNeeded = wr.RestartNeeded, wr.DockerRestartNeeded, wr.RebootNeeded
-	rep.NotCovered = notCovered(wr.Pending, blk.Ring, planned)
+	rep.RebootScanned = wr.RebootScanned
+	if layer == LayerDocker {
+		// the docker report carries the engine set only (the guest report already carries the Debian packages)
+		rep.Installed, rep.Pending = onlyDocker(wr.Installed), onlyDockerPending(wr.Pending)
+		rep.NotCovered = nil
+	} else {
+		rep.NotCovered = notCovered(wr.Pending, blk.Ring, planned)
+	}
 	return l.finish(ctx, lg, rep)
 }
 
+func onlyDocker(in []Package) []Package {
+	var out []Package
+	for _, p := range in {
+		if DockerNames[p.Name] {
+			out = append(out, p)
+		}
+	}
+	return out
+}
+
+func onlyDockerPending(in []Pending) []Pending {
+	var out []Pending
+	for _, p := range in {
+		if DockerNames[p.Name] {
+			out = append(out, p)
+		}
+	}
+	return out
+}
+
 // notCovered lists pending updates no approved release covers: in ring 0 everything outside the fast lane; in ring 1
 // also every fast-lane update the release did not name.
 func notCovered(pending []Pending, ring int, planned map[string]bool) []string {

internal/osupdate/leg_test.go

@@ -134,14 +134,14 @@ func TestRing0_OneCallPerLayer(t *testing.T) {
 		LayerHost:  {Upgraded: []Package{{Name: "openssl", Version: "u3"}}},
 	}}
 	l, h := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
-	g, ho := l.Run(context.Background(), 9201, "night")
+	g, ho := run2(l, "night")
 	if g.Outcome != "applied" || !g.Healthy || ho.Outcome != "applied" || !ho.Healthy {
 		t.Fatalf("guest %+v\nhost %+v", g, ho)
 	}
-	if calls(w) != "guest:apply,host:apply" {
-		t.Fatalf("calls = %s, want one apply per layer, guest first", calls(w))
+	if calls(w) != "guest:apply,host:apply,guest:live-restore-on,docker:apply" {
+		t.Fatalf("calls = %s, want one apply per layer, guest first, then live-restore and the ring-0 docker step", calls(w))
 	}
-	for _, p := range w.plans {
+	for _, p := range w.plans[:2] {
 		if p["select"] != "pending-fast" || p["snapshot"] != "" || len(p["packages"].([]any)) != 0 {
 			t.Fatalf("ring-0 plan = %v", p)
 		}
@@ -149,7 +149,7 @@ func TestRing0_OneCallPerLayer(t *testing.T) {
 	if len(g.NotCovered) != 1 || g.NotCovered[0] != "docker-ce" {
 		t.Fatalf("not covered = %v", g.NotCovered)
 	}
-	if len(h.reports) != 2 || h.reports[0].Layer != LayerGuest || h.reports[1].Layer != LayerHost {
+	if len(h.reports) != 3 || h.reports[0].Layer != LayerGuest || h.reports[1].Layer != LayerHost || h.reports[2].Layer != LayerDocker {
 		t.Fatalf("hub got %+v", h.reports)
 	}
 }
@@ -163,7 +163,7 @@ func TestRing1_EachLayerItsOwnRelease(t *testing.T) {
 	gr := &hub.WireOSRelease{ID: "os-g", Snapshot: "20261004T080000Z", Packages: []hub.WireOSPackage{{Name: "libc6", Version: "g-u4", Origin: "Debian"}}}
 	hr := &hub.WireOSRelease{ID: "os-h", Snapshot: "20261004T090000Z", Packages: []hub.WireOSPackage{{Name: "openssl", Version: "h-u3", Origin: "Debian-Security"}}}
 	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 1, Enabled: true, Release: gr, HostRelease: hr})
-	g, ho := l.Run(context.Background(), 9201, "night")
+	g, ho := run2(l, "night")
 	if g.ReleaseID != "os-g" || ho.ReleaseID != "os-h" {
 		t.Fatalf("release ids %q %q", g.ReleaseID, ho.ReleaseID)
 	}
@@ -182,7 +182,7 @@ func TestRing1_EachLayerItsOwnRelease(t *testing.T) {
 func TestRing1_NoReleaseIsInventory(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend}
 	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 1, Enabled: true})
-	g, ho := l.Run(context.Background(), 9201, "night")
+	g, ho := run2(l, "night")
 	if g.Outcome != "nothing" || ho.Outcome != "nothing" || calls(w) != "guest:inventory,host:inventory" {
 		t.Fatalf("g=%+v h=%+v calls=%s", g, ho, calls(w))
 	}
@@ -192,7 +192,7 @@ func TestRing1_NoReleaseIsInventory(t *testing.T) {
 func TestNoBlock_IsRing1Nothing(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend}
 	l, _ := newLeg(t, w, nil)
-	if g, _ := l.Run(context.Background(), 9201, "night"); g.Outcome != "nothing" || g.Ring != 1 {
+	if g, _ := run2(l, "night"); g.Outcome != "nothing" || g.Ring != 1 {
 		t.Fatalf("g=%+v calls=%s", g, calls(w))
 	}
 }
@@ -201,7 +201,7 @@ func TestNoBlock_IsRing1Nothing(t *testing.T) {
 func TestSwitchOff_ReportsOnly(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend}
 	l, h := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: false})
-	g, ho := l.Run(context.Background(), 9201, "night")
+	g, ho := run2(l, "night")
 	if g.Outcome != "inventory" || ho.Outcome != "inventory" || calls(w) != "guest:inventory,host:inventory" || len(h.reports) != 2 {
 		t.Fatalf("g=%+v h=%+v calls=%s", g, ho, calls(w))
 	}
@@ -212,8 +212,9 @@ func TestBYO_NoHostPlan(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend, applyRep: map[string]WrapperReport{LayerGuest: {Upgraded: []Package{{Name: "libc6"}}}}}
 	l, h := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
 	l.Appliance = false
-	_, ho := l.Run(context.Background(), 9201, "night")
-	if ho.Outcome != "" || calls(w) != "guest:apply" || len(h.reports) != 1 {
+	_, ho := run2(l, "night")
+	// the guest (and so its Docker engine) is ours on a BYO box too: only the HOST is the owner's
+	if ho.Outcome != "" || calls(w) != "guest:apply,guest:live-restore-on,docker:apply" || len(h.reports) != 2 {
 		t.Fatalf("a BYO box got a host step: host=%+v calls=%s", ho, calls(w))
 	}
 }
@@ -223,7 +224,7 @@ func TestGuestFailure_SkipsTheHost(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend, applyRep: map[string]WrapperReport{
 		LayerGuest: {Refused: json.RawMessage(`{"code":"R6","reason":"x"}`)}}}
 	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
-	g, ho := l.Run(context.Background(), 9201, "night")
+	g, ho := run2(l, "night")
 	if g.Outcome != "refused" || ho.Outcome != "" || calls(w) != "guest:apply" {
 		t.Fatalf("g=%+v h=%+v calls=%s", g, ho, calls(w))
 	}
@@ -236,7 +237,7 @@ func TestHealth_FailsAfterTheWait(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend, applyRep: map[string]WrapperReport{LayerGuest: {Upgraded: []Package{{Name: "libc6"}}, HealthAfter: bad}},
 		healthSeq: map[string][]*Health{LayerGuest: {bad, bad, bad, bad, bad, bad, bad, bad}}}
 	l, h := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
-	g, ho := l.Run(context.Background(), 9201, "night")
+	g, ho := run2(l, "night")
 	if g.Outcome != "health_failed" || g.Healthy || !strings.Contains(g.HealthReason, "app was running") || ho.Outcome != "" {
 		t.Fatalf("g=%+v h=%+v", g, ho)
 	}
@@ -251,7 +252,7 @@ func TestHealth_RecoversInsideTheWait(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend, applyRep: map[string]WrapperReport{LayerGuest: {Upgraded: []Package{{Name: "libc6"}}, HealthAfter: starting}},
 		healthSeq: map[string][]*Health{LayerGuest: {starting}}}
 	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
-	if g, _ := l.Run(context.Background(), 9201, "night"); g.Outcome != "applied" || !g.Healthy {
+	if g, _ := run2(l, "night"); g.Outcome != "applied" || !g.Healthy {
 		t.Fatalf("g = %+v", g)
 	}
 }
@@ -261,7 +262,7 @@ func TestHost_TunnelDownFailsTheHostStep(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend, applyRep: map[string]WrapperReport{LayerHost: {Upgraded: []Package{{Name: "openssl"}}}}}
 	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
 	l.Tunnel = fakeTunnel{hub.TunnelNotRunning}
-	_, ho := l.Run(context.Background(), 9201, "night")
+	_, ho := run2(l, "night")
 	if ho.Outcome != "health_failed" || !strings.Contains(ho.HealthReason, "tunnel") {
 		t.Fatalf("host = %+v", ho)
 	}
@@ -328,12 +329,12 @@ func TestHostHealthVerdict(t *testing.T) {
 func TestOncePerNight(t *testing.T) {
 	w := &fakeWrapper{t: t, pending: pend, applyRep: map[string]WrapperReport{LayerGuest: {Upgraded: []Package{{Name: "libc6"}}}}}
 	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
-	l.Run(context.Background(), 9201, "night")
+	run2(l, "night")
 	n := len(w.plans)
-	if g, _ := l.Run(context.Background(), 9201, "night"); g.Outcome != "skipped" || len(w.plans) != n {
+	if g, _ := run2(l, "night"); g.Outcome != "skipped" || len(w.plans) != n {
 		t.Fatalf("a second night run in the same night ran: %+v", g)
 	}
-	if g, _ := l.Run(context.Background(), 9201, "debug"); g.Outcome == "skipped" {
+	if g, _ := run2(l, "debug"); g.Outcome == "skipped" {
 		t.Fatal("the debug action must not be throttled")
 	}
 }
@@ -344,12 +345,144 @@ func TestWrapperSuite(t *testing.T) {
 	if err != nil {
 		t.Skip("python3 not available")
 	}
-	cmd := exec.Command(py, "-B", "../../configs/test_felhom_os_apply.py")
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		t.Fatalf("wrapper suite failed: %v\n%s", err, out)
-	}
-	if !strings.Contains(string(out), "OK") {
-		t.Fatalf("wrapper suite did not report OK:\n%s", out)
+	// the OS wrapper and (agent v0.142.0) the crash guard — both root programs in configs/ with their own suites
+	for _, suite := range []string{"../../configs/test_felhom_os_apply.py", "../../configs/test_felhom_crash_guard.py"} {
+		cmd := exec.Command(py, "-B", suite)
+		out, err := cmd.CombinedOutput()
+		if err != nil {
+			t.Fatalf("%s failed: %v\n%s", suite, err, out)
+		}
+		if !strings.Contains(string(out), "OK") {
+			t.Fatalf("%s did not report OK:\n%s", suite, out)
+		}
+	}
+}
+
+// The host's restart scan result reaches the hub with reboot_scanned, so the hub can tell "looked: not needed" (a
+// reboot cleared it) from "did not look". Red-proof: drop the RebootScanned copy in runLayer and this fails.
+func TestHostReport_CarriesRebootScanned(t *testing.T) {
+	w := &fakeWrapper{t: t, applyRep: map[string]WrapperReport{
+		LayerGuest: {},
+		LayerHost:  {RebootScanned: true, RebootNeeded: true, RestartNeeded: []string{"lxc-start"}},
+	}}
+	l, h := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
+	run2(l, "night")
+	if len(h.reports) != 3 || !h.reports[1].RebootScanned || !h.reports[1].RebootNeeded || h.reports[0].RebootScanned {
+		t.Fatalf("hub got %+v", h.reports)
+	}
+}
+
+// run2 is the guest + host reports of one pass (the tests written before the docker step).
+func run2(l *Leg, trigger string) (Report, Report) {
+	p := l.Run(context.Background(), 9201, trigger)
+	return p.Guest, p.Host
+}
+
+// ---- the Docker step (`11` §5.8, agent v0.142.0) ----
+
+// Ring 1 never takes an engine step in the night leg — only inside a signed operator job. Red-proof: drop the
+// `blk.Ring != 0` case in Run and the ring-1 pass makes a docker call.
+func TestDocker_Ring1NightLegNeverSteps(t *testing.T) {
+	w := &fakeWrapper{t: t}
+	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 1, Enabled: true})
+	p := l.Run(context.Background(), 9201, "night")
+	if p.Docker.Layer != "" || strings.Contains(calls(w), "docker") || strings.Contains(calls(w), "live-restore") {
+		t.Fatalf("ring 1 took a docker step: %s", calls(w))
+	}
+}
+
+// An unhealthy earlier step skips the docker step.
+func TestDocker_SkippedAfterAnUnhealthyStep(t *testing.T) {
+	w := &fakeWrapper{t: t, applyRep: map[string]WrapperReport{LayerGuest: {Upgraded: []Package{{Name: "libc6"}}}},
+		healthSeq: map[string][]*Health{}}
+	bad := guestOK()
+	bad.Controller = "unhealthy"
+	w.applyRep[LayerGuest] = WrapperReport{Upgraded: []Package{{Name: "libc6"}}, HealthAfter: bad}
+	w.healthSeq[LayerGuest] = []*Health{bad, bad, bad, bad, bad, bad, bad, bad}
+	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
+	p := l.Run(context.Background(), 9201, "night")
+	if p.Docker.Layer != "" || strings.Contains(calls(w), "docker") {
+		t.Fatalf("docker step ran after an unhealthy guest step: %s", calls(w))
+	}
+}
+
+// The docker plan is the slow lane, pending-docker for ring 0; the report carries only the engine set.
+func TestDocker_Ring0PlanAndReport(t *testing.T) {
+	w := &fakeWrapper{t: t, applyRep: map[string]WrapperReport{LayerDocker: {
+		Upgraded:     []Package{{Name: "docker-ce", Version: "5:29.8.2-1~debian.13~trixie"}},
+		Installed:    []Package{{Name: "docker-ce", Version: "5:29.8.2-1~debian.13~trixie", Origin: "Docker"}, {Name: "libc6", Version: "u4", Origin: "Debian"}},
+		DockerEngine: "29.8.2", Authority: "ring0"}}}
+	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
+	p := l.Run(context.Background(), 9201, "night")
+	dp := w.plans[len(w.plans)-1]
+	if dp["layer"] != "docker" || dp["lane"] != "slow" || dp["select"] != "pending-docker" {
+		t.Fatalf("docker plan = %v", dp)
+	}
+	d := p.Docker
+	if d.Outcome != "applied" || !d.Healthy || d.DockerEngine != "29.8.2" || len(d.Installed) != 1 || d.Installed[0].Name != "docker-ce" {
+		t.Fatalf("docker report = %+v", d)
+	}
+}
+
+// THE docker health rule. Red-proof: drop the id comparison (or the engine check) in DockerHealthVerdict and a case fails.
+func TestDockerHealthVerdict(t *testing.T) {
+	before := guestOK()
+	before.Containers = map[string]Container{"felhom-controller": {State: "running", Health: "healthy", ID: "a"},
+		"app": {State: "running", Health: "healthy", ID: "b"}}
+	same := guestOK()
+	same.Containers = map[string]Container{"felhom-controller": {State: "running", Health: "healthy", ID: "a"},
+		"app": {State: "running", Health: "healthy", ID: "b"}}
+	moved := guestOK()
+	moved.Containers = map[string]Container{"felhom-controller": {State: "running", Health: "healthy", ID: "a"},
+		"app": {State: "running", Health: "healthy", ID: "c"}}
+	if ok, why := DockerHealthVerdict(before, same, "29.8.2", "29.8.2"); !ok {
+		t.Fatalf("same ids, right engine: %s", why)
+	}
+	if ok, _ := DockerHealthVerdict(before, moved, "29.8.2", "29.8.2"); ok {
+		t.Fatal("a changed container id passed — live-restore failed and the apps restarted")
+	}
+	if ok, _ := DockerHealthVerdict(before, same, "29.8.2", "29.7.2"); ok {
+		t.Fatal("the engine did not move and the step passed")
+	}
+	if EngineOf("5:29.8.2-1~debian.13~trixie") != "29.8.2" {
+		t.Fatalf("EngineOf = %q", EngineOf("5:29.8.2-1~debian.13~trixie"))
+	}
+}
+
+// A changed id after the step → health_failed (the consequence, not only the verdict).
+func TestDocker_ChangedIDIsHealthFailed(t *testing.T) {
+	before := guestOK()
+	before.Containers = map[string]Container{"felhom-controller": {State: "running", Health: "healthy", ID: "a"}}
+	after := guestOK()
+	after.Containers = map[string]Container{"felhom-controller": {State: "running", Health: "healthy", ID: "z"}}
+	w := &fakeWrapper{t: t, applyRep: map[string]WrapperReport{LayerDocker: {
+		Upgraded: []Package{{Name: "docker-ce", Version: "5:29.8.2-1"}}, DockerEngine: "29.8.2",
+		HealthBefore: before, HealthAfter: after}}, healthSeq: map[string][]*Health{}}
+	w.healthSeq[LayerDocker] = []*Health{after, after, after, after, after, after, after, after}
+	l, _ := newLeg(t, w, &hub.WireOSUpdate{Ring: 0, Enabled: true})
+	p := l.Run(context.Background(), 9201, "night")
+	if p.Docker.Outcome != "health_failed" || !strings.Contains(p.Docker.HealthReason, "id changed") {
+		t.Fatalf("docker = %+v", p.Docker)
+	}
+}
+
+// R-858: a controller that cannot reach Docker fails the health rule even though its own check says healthy.
+// Red-proof: drop the ControllerDockerOK check in HealthVerdict and this fails.
+func TestHealthVerdict_ControllerBlindToDockerFails(t *testing.T) {
+	no, yes2 := false, true
+	after := guestOK()
+	after.ControllerDockerOK = &no
+	if ok, why := HealthVerdict(guestOK(), after); ok || !strings.Contains(why, "R-858") {
+		t.Fatalf("a blind controller passed: %v %q", ok, why)
+	}
+	if ok, _ := DockerHealthVerdict(guestOK(), after, "", ""); ok {
+		t.Fatal("the Docker rule passed a blind controller")
+	}
+	after.ControllerDockerOK = &yes2
+	if ok, why := HealthVerdict(guestOK(), after); !ok {
+		t.Fatalf("a seeing controller failed: %s", why)
+	}
+	if ok, _ := HealthVerdict(guestOK(), guestOK()); !ok {
+		t.Fatal("an older wrapper (no field) must not fail")
 	}
 }

internal/reconcile/classify.go

@@ -47,6 +47,10 @@ const (
 	// Destructive for unknown classes — this named constant documents the class and keeps the
 	// signed-op vocabulary explicit, it does not (and must not) loosen anything.
 	ClassAgentUpdate OpClass = "agent_update"
+
+	// A Docker engine step in the customer guest (agent v0.142.0, `11` §5.8) — ring 1, and every undo. Destructive-class
+	// (signed, operational key) like agent_update; the root wrapper re-verifies the same signature itself.
+	ClassOSDockerStep OpClass = "os_docker_step"
 )
 
 // Disposition is the classifier verdict.
@@ -115,7 +119,7 @@ func Classify(class OpClass, prov Provenance) Disposition {
 		return Destructive
 	case ClassKeyRotation:
 		return Destructive
-	case ClassAgentUpdate:
+	case ClassAgentUpdate, ClassOSDockerStep:
 		// Never benign — no agent-internal provenance can make replacing the agent binary
 		// unsigned-safe (a compromised process must not be able to self-bless an update).
 		return Destructive

internal/signedjobs/runner.go

@@ -49,6 +49,21 @@ type Executor interface {
 	Execute(ctx context.Context, op string, params json.RawMessage) error
 }
 
+type signedOpKey struct{}
+
+// WithSignedOp / SignedOpFrom carry the RAW verified envelope (blob bytes + armored signature) to an executor whose
+// ROOT half verifies it AGAIN against a root-owned key file (agent v0.142.0, the Docker slow lane: the agent's own
+// config is agent-writable, so a root wrapper must not take the agent's word for a signature).
+func WithSignedOp(ctx context.Context, s *reconcile.SignedOp) context.Context {
+	return context.WithValue(ctx, signedOpKey{}, s)
+}
+
+// SignedOpFrom returns the envelope set by WithSignedOp.
+func SignedOpFrom(ctx context.Context) (*reconcile.SignedOp, bool) {
+	s, ok := ctx.Value(signedOpKey{}).(*reconcile.SignedOp)
+	return s, ok && s != nil
+}
+
 // ErrNoExecutor signals an op class with no executor wired in this build (don't clear the job).
 var ErrNoExecutor = fmt.Errorf("signedjobs: no executor for this op class in this build")
 
@@ -158,7 +173,7 @@ func (r *Runner) processJob(ctx context.Context, j hub.JobWire) bool {
 	// Allowed: the nonce is already durably burned (Verify, before this point). Execute.
 	r.logger.Warn("signedjobs: AUTHORIZED signed op — executing",
 		"job", j.JobID, "op", ob.Op, "key_id", dec.Verified.KeyID, "nonce", dec.Verified.Nonce)
-	err := r.exec.Execute(ctx, ob.Op, ob.Params)
+	err := r.exec.Execute(WithSignedOp(ctx, signed), ob.Op, ob.Params)
 	switch {
 	case err == nil:
 		r.logger.Warn("signedjobs: signed op COMPLETED", "job", j.JobID, "op", ob.Op)