docs(remediation): bank D-51 — merged, closed, and the running tool is still broken

#1032 merged 58b971ab and #1019 closed, both verified by property. RM-03 is delivered to main. And the
guard that actually executes on this host is unchanged: installed 291 lines with ZERO occurrences of
ASSERTED_NOT_READY, main 482 lines with five. Differing SHA-256. Measured, not inferred — the installed
guard contains none of the tri-state logic.

This is the install-drift disease the postmortem indicts, caught in the act on the mission's own fix.
Every completion signal is green — merged PR, closed issue, terminal CI, merge-gate GO — and the defect
is still live in the thing that runs. D-23's origin was an assumed-propagated-but-didn't guard; this is
that origin reproduced by the delivery of its own remedy.

Merge is not delivery for tool changes. Rules banked from Mos: propagate only via the canonical path
(mosaic upgrade / deploy pipeline), never a hand-copy that could diverge while appearing to fix it; the
installed guard stays zero-information until re-sync, so every state=unknown exit 0 this mission logged
remains correctly uncited; and on re-sync VERIFY THE PROPERTY by running the installed guard against a
known-red pipeline to confirm it exits non-zero and blocks. Closing this by assuming the upgrade worked
would reproduce D-23 a third time.

Generalises: every framework/tool change this mission delivers has the same main-to-installed gap. It
belongs on the completion checklist for tool-affecting tasks and mechanically on RM-63 — the same
systemd-service architecture that mechanises rotation also mechanises propagation.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

docs/remediation/TASKS.md

@@ -586,6 +586,45 @@ is that discipline without a mechanism eventually fails."_
 > a failed round **or by a lucky manual sweep.** Interim: both coordinator and orchestrator sweep — and
 > **the mechanism retires the sweep.**
 
+### D-51 — the fix is merged, the issue is closed, and the RUNNING TOOL IS STILL BROKEN
+
+`#1032` merged (`58b971ab`), `#1019` closed, both verified by property. **RM-03 is delivered to `main`.**
+And the guard that actually executes on this host is unchanged:
+
+| artifact                                     | lines | `ASSERTED_NOT_READY` |
+| -------------------------------------------- | ----- | -------------------- |
+| `main:.../tools/git/ci-queue-wait.sh`        | 482   | **5**                |
+| **installed** `~/.config/mosaic/tools/git/…` | 291   | **0**                |
+
+**The installed guard contains NONE of the tri-state logic.** Measured, not inferred: differing SHA-256,
+191 fewer lines, zero occurrences of the marker the fix is built around.
+
+> **★ THIS IS THE INSTALL-DRIFT DISEASE THE POSTMORTEM INDICTS, CAUGHT IN THE ACT ON THE MISSION'S OWN
+> FIX.** A correct fix on `main` that never reaches the running tool. Every completion signal is green —
+> merged PR, closed issue, terminal CI, merge-gate GO — and **the defect is still live in the thing that
+> actually runs.** D-23's origin was an assumed-propagated-but-didn't guard; this is that same origin
+> reproduced by the delivery of its own remedy.
+
+**MERGE IS NOT DELIVERY FOR TOOL CHANGES.** The propagation is a **required delivery step**, tracked,
+not a consequence of merging.
+
+**Rules (Mos, 2026-08-01):**
+
+1. **Canonical path only** — `mosaic upgrade` / the deploy pipeline. **NOT a hand-copy**, which can
+   diverge and would reintroduce drift while appearing to fix it. (Likely needs Jason's gated
+   `mosaic upgrade`; Mos is flagging it.)
+2. **The installed guard stays ZERO-INFORMATION until re-sync** — keep recording it as such. Every
+   `state=unknown exit 0` this mission has logged remains correctly uncited.
+3. **★ ON RE-SYNC, VERIFY THE PROPERTY, DO NOT ASSUME PROPAGATION.** Run the **installed** guard against
+   a **KNOWN-RED** pipeline and confirm it exits **non-zero and BLOCKS**. _Assumed-propagated-but-didn't
+   is exactly D-23's origin_ — closing this finding by assuming the upgrade worked would reproduce it a
+   third time.
+
+**Generalises beyond this guard:** any framework/tool change delivered by this mission has the same gap
+between `main` and the installed surface. Belongs on the completion checklist for every tool-affecting
+task, and mechanically on **RM-63** (systemd-managed services re-seeded on restart) — the same
+architecture that mechanises rotation also mechanises propagation.
+
 ### D-50 — a GO has a SHELF LIFE: a gate-ready PR held too long goes stale under main drift
 
 `#1032` (RM-03, the queue-guard fix) carried **review 66 APPROVED and a merge-gate GO, both bound to