wip(rm-03): rescue checkpoint of in-flight queue-guard work

CHECKPOINT ONLY — not a deliverable, not reviewed, not complete.

Committed by mos-remediation as TRANSPORT after the authoring seat (coder-mos1) became
unable to act: its context window was exceeded at 102.6%/372k AND its overflow-recovery
path failed ("Turn prefix summarization failed: servers overloaded"). The seat could not
process instructions or commit its own work, leaving 28 modified files durable only on
local disk.

Authorship preserved as coder-mos1 — this is transport, not authorship. The work is the
seat's; committing it is the only way to make it survive the rotation that must follow.

Scope note, unresolved: this diff spans the queue-guard tools (9 files under
framework/tools/git) AND 5 framework guides plus 11 agent templates. RM-03 was scoped to
ci-queue-wait.sh and its tests. Whether the doc/template edits are consequential to the
tri-state change or drive-by was queried and never answered — the seat was bricked before
it could reply. That question stays open and must be resolved before any of this is
reviewed; the wider edits may need splitting out.

Direct instance of D-31: commit-then-rotate works, rotate-without-commit loses everything.

packages/mosaic/framework/guides/CODE-REVIEW.md

@@ -13,7 +13,7 @@ Merge strategy enforcement (HARD RULE):
 - PR target for delivery is `main`.
 - Direct pushes to `main` are prohibited.
 - Merge to `main` MUST be squash-only.
-- Use `~/.config/mosaic/tools/git/pr-merge.sh -n {PR_NUMBER} -m squash` (or PowerShell equivalent).
+- Use `~/.config/mosaic/tools/git/pr-merge.sh -n {PR_NUMBER} -m squash --expect-head {approved_full_sha}` (or PowerShell equivalent).
 
 ## Review Checklist