fix(ci): unshallow gate replay history

docs/ADMIN-GUIDE/quality-gate-registry.md

@@ -26,8 +26,8 @@ Do not add an ownerless exception or describe an open delta as pass/green/OK.
 
 ## CI behavior
 
-Woodpecker runs `gate-verify` on every pull request and protected-main push without path filtering. This is deliberate: changes outside gate files can make a gate inert.
+Woodpecker runs `gate-verify` on every pull request and protected-main push without path filtering. This is deliberate: changes outside gate files can make a gate inert. The step unshallows the checkout first because prospective ancestry and own-tree replay require complete commit history; a shallow boundary must never be interpreted as non-ancestry.
 
 Provider evidence input is an optional JSON array of normalized pipeline records containing `commit`, unique integer pipeline `number`, pipeline `status`, and a `gate-verify` step status. The highest numbered rerun is authoritative; ambiguous duplicates fail. Its retention window is provider-controlled and is not overstated by this repository.
 
-Prior commit replay performs a frozen offline install from each commit's own lockfile before running that commit's verifier. Bubblewrap clears the environment, hides operator-home credentials, and disables networking for historical lifecycle and verifier code. A missing cached dependency or unavailable sandbox fails replay; current dependencies are never substituted.
+Prior commit replay performs a frozen offline install from each commit's own lockfile before running that commit's verifier. Bubblewrap clears the environment, hides operator-home credentials, isolates process namespaces, and disables networking for historical lifecycle and verifier code. Archived files are snapshotted before install and must remain byte/type/mode-identical afterward. A missing cached dependency, source mutation, or unavailable sandbox fails replay; current dependencies are never substituted.

docs/scratchpads/1029-rm-02-gate-registry.md

@@ -58,6 +58,7 @@ The queue guard's `get_state_from_status_json` runs `python3 - <<'PY'` while pro
 - Codex security review found the Bubblewrap replay shared the runner PID namespace. Replay now unshares PID, IPC, and UTS namespaces, and an abuse-case test proves a sibling runner PID is invisible.
 - Second review found empty reason diagnostics, final-symlink fixture writes, and lifecycle-script mutation of authoritative history files. Must-fail cases now require a reason pattern; writes use no-follow semantics; and replay snapshots every archived file before install and rejects any changed, deleted, or type/mode-shifted source before executing the verifier. Dedicated negative tests cover all three.
 - Third code review found ambiguous duplicate provider steps and order-sensitive JSON outcome comparison. Provider evidence now requires exactly one `gate-verify` step in the authoritative rerun, and structural equality normalizes object keys. Both regressions have RED-first tests. Third security review reported no findings.
+- Initial PR pipeline #2177 exposed Woodpecker's shallow boundary: the activation parent object was present but marked shallow, so `merge-base --is-ancestor` correctly refused to infer ancestry. The unconditional gate step now unshallows before prospective replay; its wiring test was observed RED before the CI fix.
 
 ## Documentation checklist