test(ci): classify Bubblewrap EPERM exactly

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

@@ -39,7 +39,7 @@ Deliver the seven-gate registry and RED-first anti-inert verifier on `feat/rm-02
 - CI wiring RED: package script and unconditional Woodpecker step tests both failed before wiring.
 - History RED: history test failed with missing module before own-tree manifest selection/provider classification was implemented.
 - `pnpm gate:verify`: exit 0; seven gates each reported `META-NEGATIVE-CONTROL ... observed red`; queue source/deployed drift control observed red; six queue behavior deltas printed as `DEFECT (owner: RM-03)`.
-- Focused Node tests: 34/34 pass after review hardening (24 verifier/wiring plus 10 history/provider tests).
+- Focused Node tests: 35/35 pass after review hardening (24 verifier/wiring plus 11 history/provider tests).
 - `pnpm typecheck`: pass (45/45 Turbo tasks).
 - `pnpm lint`: pass (25/25 Turbo tasks).
 - `pnpm format:check`: pass.
@@ -61,7 +61,7 @@ The queue guard's `get_state_from_status_json` runs `python3 - <<'PY'` while pro
 - 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 ancestry/provenance checks; its wiring test was observed RED before the CI fix.
 - Pipeline #2178 then proved the unprivileged Docker runner cannot establish Bubblewrap namespaces. A privileged experiment remained uncommitted and was rejected after Codex correctly rated it CRITICAL: PR-controlled code executes before an in-repository sandbox and could directly use the granted capability.
 - `mos-remediation` and `rev-974` independently ruled Option C. RM02-REQ-10 now retains its original text, restatement, and reason: PR CI verifies only the current tree, unprivileged and fail-closed; isolated own-tree replay is deferred to RM-60/#1031's external pre-execution authority, cross-referenced with RM-59. Future protected post-merge replay is detection with quarantine/revert, never pre-merge prevention.
-- RED-first boundary test proved the old path executed an inert intermediate verifier. The revised path states adjacent `DOES`/`DOES NOT` claims, validates historical manifest provenance without executing it, and infers no replay success. Direct sandbox tests remain hard-fail; unprivileged CI asserts terminal refusal instead of treating replay as success.
+- RED-first boundary test proved the old path executed an inert intermediate verifier. The revised path states adjacent `DOES`/`DOES NOT` claims, validates historical manifest provenance without executing it, and infers no replay success. Direct sandbox tests remain hard-fail; unprivileged CI asserts terminal refusal instead of treating replay as success. Pipeline #2179 showed this runner reports namespace denial as `spawnSync bwrap` with `error.code=EPERM`, `status=null`, and no stderr; the refusal detector now recognizes only that Bubblewrap-provenance hard-fail form and rejects unrelated command EPERM results.
 - Option C security review reported no findings. Code review rejected an initial unrelated typecheck binding for the new security criterion. It was replaced with a dedicated registered `privileged-pr-gate` case: the fixture injects a privilege key into the gate step, the wiring control rejects it for that exact reason, and `gate:verify` observes the boundary negative control. Follow-up hardening uses a closed exact gate-step construction, rejects privilege across the entire pipeline, rejects non-canonical/merged YAML keys, and pins the unrestricted PR/main trigger block; quoted/escaped/alias/merge/duplicate/filter bypass tests pass. Final Codex code review approved with no findings.
 
 ## Documentation checklist

scripts/gate-history.test.mjs

@@ -16,7 +16,12 @@ const fixtureRoot = path.join(process.cwd(), '.mosaic-test-work', `gate-history-
 
 function sandboxUnavailable(result) {
   const detail = `${result.stdout ?? ''}${result.stderr ?? ''}${result.error?.message ?? ''}`;
-  if (!/bwrap:.*(?:Operation not permitted|Creating new namespace failed)/i.test(detail)) {
+  const bubblewrapSpawnDenied =
+    result.error?.code === 'EPERM' && /spawnSync bwrap/i.test(result.error?.message ?? '');
+  if (
+    !bubblewrapSpawnDenied &&
+    !/bwrap.*(?:EPERM|Operation not permitted|Creating new namespace failed)/i.test(detail)
+  ) {
     return false;
   }
   assert.notEqual(result.status, 0, 'sandbox unavailability must remain terminal nonzero');
@@ -44,6 +49,23 @@ test.after(async () => {
   await rm(fixtureRoot, { recursive: true, force: true });
 });
 
+test('sandbox refusal classification requires Bubblewrap provenance', () => {
+  assert.equal(
+    sandboxUnavailable({
+      status: null,
+      error: { code: 'EPERM', message: 'spawnSync bwrap EPERM' },
+    }),
+    true,
+  );
+  assert.equal(
+    sandboxUnavailable({
+      status: null,
+      error: { code: 'EPERM', message: 'spawnSync git EPERM' },
+    }),
+    false,
+  );
+});
+
 test('prospective history reads each commit own manifest rather than the current tree', async () => {
   await rm(fixtureRoot, { recursive: true, force: true });
   await mkdir(fixtureRoot, { recursive: true });