docs: publish-train rules — coupled-release gates codified (option-2)

manifest-before-floor; floor field LAST (hub_settings DB row overrides env, acts
immediately — the 0.81/0.113 9-minute skew incident); MinAgent fleet gate
(controller CHANGELOG header convention from ctrl v0.114.0); the controller
capability gate as box-level backstop.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PSK5g6qYLknKj8u3QAFEr6

CONTEXT.md

@@ -3,6 +3,15 @@
 > Created with the REUSE.md rollout (2026-07-03). Authoritative history: `hub/CHANGELOG.md` (hub),
 > `website/CHANGELOG.md`, `scripts/CHANGELOG.md`; end-of-task detail in `REPORT.md`.
 
+- **2026-07-11 — PUBLISH-TRAIN RULES CODIFIED** (`documentation/runbooks/publish-train-rules.md`,
+  option-2 of the skew answer): 1. manifest before floor; 2. the manifest screen carries the LIVE
+  DB floor (`hub_settings.min_controller_version` overrides env, acts immediately) — save the floor
+  field LAST; 3. MinAgent fleet gate (controller CHANGELOG header convention from ctrl v0.114.0;
+  floor may not rise past an unmet MinAgent — hub dashboard check, manual at current fleet size;
+  hub-enforced per-box gating = deferred option-3); 4. box-level backstop = controller v0.114.0's
+  agent-capability gate (route probe, felhom-controller `internal/agentapi/features.go`). Hub
+  UNTOUCHED (floor-UI separation = its own future task).
+
 - **2026-07-11 — PUBLISH TRAIN 0.81/0.113 COMPLETE — PETI LIVE on agent 0.81.0 + controller 0.113.0.**
   Record: `documentation/pilot/RUNBOOK-publish-0.81-0.113-2026-07-11.md`. Agent 0.81.0 published
   (sha `914bb3b5…30df0b`, live-bytes, anon-verified) + golden 0.113.0 baked/published (sha

documentation/runbooks/publish-train-rules.md

@@ -0,0 +1,47 @@
+# Publish-train rules — coupled controller/agent releases
+
+Standing gates for every artifact publish train (agent binary + controller golden + Day-0 manifest +
+floor). Each rule cites the incident that created it. The box-level backstop (rule 4) exists because
+rules 1–3 are operator discipline and discipline fails; the rules stay the primary control.
+
+## 1. Manifest before floor (the GL-1 rule, restated)
+
+Publish and vouch the artifacts in the Day-0 manifest **before** any floor movement. A floor that
+points at an unvouched (or unpublished) version bricks self-updates: boxes are told to move to a
+version they cannot verify. (GL-1 supply-chain arc; see the go-live package records.)
+
+## 2. The manifest screen carries the LIVE DB floor — save the floor field LAST
+
+The hub's Day-0 manifest UI also persists the global floor as a DB row
+(`hub_settings.min_controller_version` — `hub/internal/store/store.go`,
+`GetGlobalMinControllerVersion`). **The DB row overrides the env floor and acts immediately on the
+next report cycle** — it is not staged by the manifest vouch.
+
+**Incident:** publish train 0.81/0.113 (2026-07-11,
+`documentation/pilot/RUNBOOK-publish-0.81-0.113-2026-07-11.md`): the operator saved the manifest
+screen with the floor field filled; the floor acted at once and controller 0.113.0 reached Peti's
+box ~9 minutes **before** agent 0.81.0 — the exact forbidden skew, benign only because the box had
+zero NAS shares.
+
+**Rule:** fill the floor field **last**, in a separate save, only after rule 3's fleet check passes.
+
+## 3. MinAgent fleet gate
+
+A controller release that depends on coupled agent behavior declares `MinAgent: X.Y.Z` in its
+CHANGELOG entry header line (felhom-controller convention, since v0.114.0; retroactively, 0.113.0's
+effective MinAgent was 0.81.0 for the NAS add). **The floor may not rise past a controller version
+whose MinAgent is not yet met fleet-wide:** check the hub dashboard — every reporting box must show
+agent ≥ MinAgent before the floor save. Manual at the current fleet size; hub-enforced per-box
+gating is the deferred option-3.
+
+## 4. Box-level backstop: the controller's capability gate
+
+Since controller v0.114.0, a coupled feature entry point probes the agent's capability
+(`controller/internal/agentapi/features.go` — route probe: 2xx ⇒ supported, 404 ⇒ older agent,
+transport/5xx ⇒ indeterminate, never "too old") and refuses up front with an honest Hungarian
+message instead of failing mid-pipeline. This turns a violated ordering into a graceful refusal —
+it does **not** license sloppy trains: rules 1–3 remain the primary control.
+
+Convention for new coupled features: add a row to the `featureProbes` table + a `Supports` gate
+call at the feature's entry point, and declare MinAgent per rule 3. When the agent someday reports
+an explicit version in its envelope, `Supports` should prefer the version comparison (roadmap).