# REPORT — green-gate restoration + F7 export-page fix + remediation-arc cleanup

**Date:** 2026-07-20 · **Repo:** felhom-controller (v0.149.0 → **v0.150.0**) · Trunk, pushed to `main`.
**Origin:** the three open hygiene items from the 2026-07-20 remediation arc (REPORT §Green gate,
§Observations) + R-53.

---

## 1. Baselines used

| Repo | Baseline @ start | Gate | After |
|------|------------------|------|-------|
| felhom-controller | `4646be1` | `HEAD == origin/main`, tree clean ✔ | `9f436c8` (code), then this docs commit |
| felhom.eu | `30fd9d3` | `HEAD == origin/main` ✔ | `1e11819` (ROADMAP) |

Deployed controller **before**: `felhom-controller:0.149.0` (Up, healthy) — matched the baseline.
Deployed controller **after**: `felhom-controller:0.150.0` (Up 6 seconds, healthy).

---

## 2. Part 1 — the 7 red `internal/backup` tests

### 2.1 Classification (1.1) — one class, not several

The v0.149.0 REPORT's device-identity hypothesis is **confirmed**, and the code said so in Hungarian
without anyone having to infer it. `TestSharesTier2MirrorsBothClasses` failed with:

```
LastStatus:no_target
LastError:/tmp/…/hdd_1: nincs másik fizikai meghajtó — a 2. mentéshez 2. meghajtó szükséges
```

Tier-2's whole purpose is to refuse a target on the source disk; it asks
`system.SamePhysicalDevice` → `isSameBlockDevice` → `statA.Dev == statB.Dev`
(`internal/system/mounts_linux.go:225`). On DooPlex every `t.TempDir()` lands on one filesystem, so a
fixture's `hdd_1` and `hdd_2` share an `st_dev`, the guard correctly refuses, and the test can never
reach the behaviour it exists to check. **The tests were right and the code was right — the
environment could not express the fixture's premise.**

| Test | Failing assertion | Root-cause class |
|---|---|---|
| `TestSharesTier2MirrorsBothClasses` | shares not mirrored; payload + marker missing; `LastStatus != ok` | device-identity |
| `TestSharesTier2SkipsDeadMountAndContinues` | "the healthy share must still be mirrored" | device-identity |
| `TestSharesTier2ReconcilePrunesRemovedShare` | precondition: dest dir absent after first run | device-identity |
| `TestSharesTier2NotifierNeverLeaksReservedKey` | "precondition: the notifier should have fired" | device-identity |
| `TestTier2V2_MigrationAndMarkerLast` | flat `appdata/` not removed; legs not mirrored; no marker | device-identity |
| `TestTier2V2_Reconcile` | stale sibling / unrelated dirs not reconciled away | device-identity |
| `TestTier2V2_NetworkExclusion` | picked `…/sys/felhom-data` instead of the local drive | device-identity |

**No test failed for a non-environmental reason** — no real defect was found hiding behind the red,
so there is no §1.1 STOP finding.

### 2.2 Fix — tool 2 (minimal seam), once, for all seven

Tool 1 (test-only) was considered and rejected: the only way to get two genuinely distinct devices
on this host is to place one fixture drive on `/mnt/5_hdd` and the other on `/tmp`, which hard-codes
DooPlex's disk layout into the tests — non-hermetic, and it would re-break on any other machine. Tool
3 (`t.Skip`) would have hidden seven real assertions behind an environment excuse.

**The seam** (`internal/backup/backup.go`) — one field + one wrapper, modelled on the package's
existing `tier2Mirror` / `tier2SSDFits` / `sharesPassdbCapture` nil-defaulted field seams:

```go
samePhysicalDevice func(a, b string) bool   // nil → system.SamePhysicalDevice

func (m *Manager) sameDevice(a, b string) bool {
	if m.samePhysicalDevice != nil { return m.samePhysicalDevice(a, b) }
	return system.SamePhysicalDevice(a, b)
}
```

**Seam justification (one line, per §9.4):** the off-drive predicate is the single environmental fact
the tier-2 tests cannot supply on a one-filesystem host; routing it through a nil-defaulted field
makes it injectable while leaving production on the identical `st_dev` call.

Nil-check lives in the wrapper rather than in `NewManager` deliberately: `newSharesEnv` builds
`&Manager{…}` by literal, so a constructor-only default would leave the field nil and panic.

Seven call sites now go through `m.sameDevice(...)`: `tier2.go` ×5 (`selectTier2TargetFrom` ×3,
`RunTier2`, `Tier2Info`), `tier2_shares.go` ×1 (`RunSharesTier2`), `backup.go` ×1
(`hasOffDriveTarget`). Behaviour with a nil seam is byte-for-byte the previous code.

**Test-side** (`device_seam_test.go`, new): `oneDrivePerSubtree` models one drive per directory
subtree — two paths share a device only when one contains the other, which is exactly how real
mountpoints behave. Installed in the two fixtures only (`newTier2V2`, `newSharesEnv`).

Nothing was weakened: the guard still runs and still refuses same-device targets — the
same-drive refusal test `TestSharesTier2NeverTargetsItsOwnSourceDrive` passes under the seam, and it
is the test that would catch a fake that simply said "always different".

**Surviving `t.Skip`s: none.** No test was skipped, deleted, renamed, or had an expected value
changed.

### 2.3 Scenario B — mutation table

Every one of the seven had the defect it guards re-introduced in **production** code, one at a time,
then reverted:

| Test | Mutation | Result |
|---|---|---|
| `TestSharesTier2MirrorsBothClasses` | skip the payload mirror to the target | **FAIL** ✔ |
| `TestSharesTier2SkipsDeadMountAndContinues` | stop skipping `Disconnected/Decommissioned` drives | **FAIL** ✔ (`dead-mount share reached a mirror call`) |
| `TestSharesTier2ReconcilePrunesRemovedShare` | `tier2ReconcileRoots` → no-op | **FAIL** ✔ |
| `TestSharesTier2NotifierNeverLeaksReservedKey` | pass `SharesPseudoStack` raw on the success path | **FAIL** ✔ (`the reserved key reached the notification boundary raw: "_shares"`) |
| `TestTier2V2_MigrationAndMarkerLast` | skip the old-flat-`appdata/` migration cleanup | **FAIL** ✔ |
| `TestTier2V2_Reconcile` | `tier2ReconcileRoots` → no-op | **FAIL** ✔ |
| `TestTier2V2_NetworkExclusion` | disable the auto `sp.IsNetwork()` skip | **FAIL** ✔ |

Honest note on method: my first attempt at two of these mutated the wrong code path (the
mirror-failure notify branch instead of the success one; the unregistered-root skip instead of the
disconnected-drive one) and both tests stayed green. That was a bad mutation, not a hollow test — the
corrected mutations bite, and the notifier one reproduces that test's own documented red-proof
verbatim. Tree verified free of mutation residue afterwards (`grep -c "// MUT:"` → 0).

### 2.4 Scenario A — green gate, twice

| Run | Command | Result |
|---|---|---|
| build / vet | `go build ./...`, `go vet ./...` | **OK** |
| 1 | `go test ./... -count=1` | **exit 0 — 23 packages ok, 0 FAIL** |
| 2 | `go test ./... -count=1` | **exit 0 — 23 packages ok, 0 FAIL** |

`grep -c SKIP` over run 2 → **0**. The gate is genuinely green, not green-by-omission.

---

## 3. Part 2 — F7 / R-53, the export page

`app_export.html` L93 read `var domain = '{{.Stack.Meta.Subdomain}}' ? '{{…}}.{{$.CSRFToken}}' : '';`
— the session CSRF token where the customer domain belongs.

**A spec premise turned out to be wrong, and the fix needed one more line than planned.** §5 states
`{{$.Domain}}` is "set by `baseData`". It is (`handlers.go:120`) — but `exportPageHandler`
(`handler_export.go`) never calls `baseData`; it builds `{"Stack", "Drives"}` and `executeTemplate`
injects only `CSRFField` / `CSRFToken`. Swapping the token alone would have rendered an empty
domain — trading a wrong link for a broken one. So the fix is two lines:

- template: `{{$.CSRFToken}}` → `{{$.Domain}}`;
- handler: `"Domain": s.cfg.Customer.Domain` added to the map, mirroring `baseData`'s own line.

`csrfH()` and the meta-tag CSRF flow are the correct usage and are untouched.

**Tests** (`app_export_domain_test.go`, new — v0.149.0's render harness): the `var domain` line is
isolated first so an assertion cannot match the token where it legitimately appears (the meta tag).

| Scenario | Test | Result |
|---|---|---|
| C — joined from the customer domain, token absent | `TestAppExportDomainUsesCustomerDomainNotCSRFToken` | **PASS** |
| C — empty-subdomain branch still `''` | `TestAppExportDomainEmptyWithoutSubdomain` | **PASS** |

**Red-proof:** restored the pre-fix template line → both tests fail, showing the defect verbatim:

```
--- FAIL: TestAppExportDomainUsesCustomerDomainNotCSRFToken
    export link must be built from the customer domain, got:
      var domain = 'photos' ? 'photos.deadbeefcafebabe…' : '';
    the CSRF token must NEVER appear in the export URL, got: … (same line)
--- FAIL: TestAppExportDomainEmptyWithoutSubdomain
```

Template restored; both green.

**Live verification (Scenario C)** — authenticated endpoint fetch of the real export page
`/stacks/immich/export` (no browser on DooPlex), ASCII-safe grep per the new gotcha:

```
line 237:  var domain = 'photos' ? 'photos.demo-felhom.eu' : '';
meta tag:  csrf-token" content="f7f928f1…      ← the token lives here, and only here
```

The rendered link is correct and the token appears nowhere in it. Note this also confirms the
handler-side `Domain` key, which the render tests alone could not prove.

---

## 4. §3.4 — the orphaned `dhclient`

Evidence first. Exactly one match, on an interface that does not exist:

```
BEFORE: 1922 /sbin/dhclient -pf /run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases eth0
        PPID 1652, started Mon Jul 20 07:25:30 (boot)
interfaces: lo enp1s0 wlp2s0 tailscale0 vmbr0 wg-felhom veth9201i0   ← no eth0
vmbr0: iface vmbr0 inet static / address 192.168.0.162/24            ← no dhclient should run at all
neither /run/dhclient.eth0.pid nor /var/lib/dhcp/dhclient.eth0.leases existed
```

Killed. Re-checked immediately and again ~25 min later: `pgrep -a dhclient` → **none, no respawn**.
`vmbr0` still `192.168.0.162/24`, `felhom-agent` still `active`. No other host mutation.

---

## 5. Files changed

| File | Change |
|------|--------|
| `internal/backup/backup.go` | seam field + `sameDevice` wrapper; 1 call site routed |
| `internal/backup/tier2.go` | 5 call sites routed through the seam |
| `internal/backup/tier2_shares.go` | 1 call site routed; unused `system` import dropped |
| `internal/backup/device_seam_test.go` | **new** — `oneDrivePerSubtree` |
| `internal/backup/tier2_v2_test.go`, `shares_test.go` | seam injected in the two fixtures (1 line each) |
| `internal/web/templates/app_export.html` | 1 token: `{{$.CSRFToken}}` → `{{$.Domain}}` |
| `internal/web/handler_export.go` | `"Domain"` added to the export page's data map |
| `internal/web/app_export_domain_test.go` | **new** — 2 tests + 2 helpers |
| `CLAUDE.md` | 2 gotchas in the live-validation section |
| `CHANGELOG.md` / `CONTEXT.md` / `REPORT.md` | v0.150.0 bookkeeping |

**Commits:** felhom-controller `9f436c8` (code) + this docs commit; felhom.eu `1e11819` (ROADMAP).

---

## 6. ROADMAP corrections (felhom.eu)

- **R-50 factual correction.** The entry claimed an address move needs the cert's SAN set to cover
  the new address. Read against source (`internal/agentapi/client.go` L105–129): the controller→agent
  leg sets `InsecureSkipVerify: true` and replaces chain verification with a `VerifyPeerCertificate`
  that does a raw **SHA-256 match on the leaf DER**. Hostname/SAN never enters verification on this
  leg, so an address move most likely needs **no cert re-issuance** — only the endpoint the guest
  dials. The entry now says so, and still requires the spike to confirm it empirically.
- **R-53 collapsed** to its one-liner + **SHIPPED (controller v0.150.0)**, noting the handler-side
  `Domain` key as part of the fix.

---

## 7. Not done / open

R-50 (durable F1 — spike-first, not started), R-51, R-52, R-39(b)/F6 — all untouched, as scoped.

---

## 8. Observations (noticed, not acted on)

1. **Four files in `internal/backup` are not `gofmt`-clean at HEAD** — `offbox_3a_test.go`,
   `recovery_unit.go`, `tier2.go`, `tier2_v2_test.go`. I verified this is **pre-existing** (checked
   each file's HEAD blob through `gofmt -l` before my edits) and left them alone: `gofmt` is not part
   of the green gate (`build`/`vet`/`test`), and reformatting them would have buried this task's real
   diff in noise. Worth a one-shot `gofmt -w` pass in its own commit.
2. **`system.SamePhysicalDevice` is mount/device-granular, not disk-granular** — its own doc comment
   says two partitions on one physical disk look "different" here, with the agent's durable-id as the
   stronger guarantee. Unchanged by this work, but it means the tier-2 off-drive promise is
   partition-level on a box that partitions one disk.
3. **The tier-2 tests silently stopped exercising their subject rather than failing loudly at the
   premise.** Each failed on a downstream assertion ("share was not mirrored") instead of on "this
   fixture needs two devices and this host has one". A fixture-level precondition check would have
   turned a week of ambiguous red into one clear message.