fix(webui): arm the recovery gates and make the playbooks reach the process (#644)

Reviewer REQUEST_CHANGES on PR #903 at head 1c88b87 raised five blockers, all
reproduced by executing that head. The shared shape: a write path that declared
itself gated, audited, and verified, but never armed the gate, mutated a copy of
the state it claimed to fix, and then verified against that same copy.

B1 - the apply path never asked the execution gate.
execute_recovery_playbook called console_authz.authorize with the default
for_execution=False, and the phase branch only fires when it is True. ACTIVE_PHASE
is 1 and every new action is phase 2, so an operator executed a phase-2 write
through POST /api/v1/system/recovery/apply while build_recovery_preview reported
execution_enabled false. The call now passes for_execution=True and surfaces the
phase_not_active refusal. Preview reports the same decision under
execution_authorization / execution_blocked_reason instead of a hardcoded False it
could not explain.

B2 - both env playbooks mutated a discarded copy and verified against it.
source_env = dict(os.environ) meant clear_stale_binding and rebind_session_worktree
never touched the running process, and verify_post_recovery(env=source_env)
re-diagnosed the same copy, confirming a change that had not happened. Mutations
now target the live mapping (apply_recovery's sanctioned env=None -> os.environ
path, #702 AC2) and verification re-reads state rather than the mutated input.
binding_before / binding_after / binding_changed are returned, and a playbook that
changed nothing reports performed: false. verify_post_recovery no longer reads an
unverified_inherited binding as clean, because unproven is not clean.

B3 - the reconcile playbook called a function that does not exist.
merged_cleanup_reconcile.reconcile_merged_cleanups is absent from that module and a
bare except turned the AttributeError into a generic failure, so the playbook could
never succeed. It now calls gitea_mcp_server.gitea_reconcile_merged_cleanups, the
real orchestrator, imported lazily; failures carry error_type. task_capability_map
declared gitea.pr.close for reconcile_cleanups while the entry point gates on
gitea.read; the two authority statements are reconciled to the one that is enforced.

B4 - the #630 contamination integration could not block.
assess_contamination_gate was fed marker=None, which short-circuits to block: False
on its first statement; the task passed was a console action id outside
CONTAMINATION_GATED_TASKS; and the result was read through a "contaminated" key the
gate never returns, making STATUS_BLOCKED_CONTAMINATION unreachable. The live marker
now comes from the #641 session inventory reader, the gated task key
console_recovery_apply is added to CONTAMINATION_GATED_TASKS, every read uses the
"block" key the gate actually returns, and the marker is forwarded to
sanctioned_restart.execute_restart so a restart cannot launder a contaminated
runtime. The reconciler cleanup playbook stays exempt as the designated remedy.

B5 - the parity baseline was captured from the head it was compared against.
capture_startup_parity(root, head=checkout_head) stores the head verbatim, so
in_parity was structurally incapable of being false, and live_remote_head was never
passed. The baseline is now the daemon start head that assess_stale_runtime already
returns, and the #610 live-remote dimension is restored.

Also: _recovery_card was the one renderer in system_health_views.py interpolating
without _esc(), and it is where a marker's operator-supplied command_summary lands
once B4 is wired; it now escapes, including the except branch. Docs no longer claim
apply enforces master parity or that verify asserts clean: true, and the absolute
file:///Users/... links are relative.

Tests: the two that asserted the defects as intended are inverted -
test_api_recovery_apply_with_dev_auth asserted the phase-gate bypass, and the rebind
test asserted the input echoed back. Added coverage per blocker, including a no-op
detection test that fails when a playbook reports success without changing anything,
the previously untested reconcile playbook, contamination block and remedy-exemption
tests, and parity baseline/live-remote tests. Both new guards were mutation-verified:
disarming for_execution fails 2 tests, restoring the env copy fails 2 tests.

Validation: WEBUI_TEST_OFFLINE=1 ../../venv/bin/python -m pytest tests/ -q from
branches/feat-issue-644 gives 27 failed / 5291 passed / 6 skipped / 953 subtests;
the same command from branches/baseline-master-76f293e at 76f293eb28 gives
28 failed / 5262 passed / 6 skipped / 926 subtests. Suites run one at a time.
comm of the sorted FAILED lines shows no new signature at the head. The single
absent signature, test_workspace_guard_alignment.py::
TestRuntimeContextGuardAlignment::test_declared_branches_worktree_passes_when_mcp_root_differs,
is suite-order dependent: that file passes 9/9 in isolation at both revisions.

Closes #644

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

stable_branch_push_guard.py

@@ -63,6 +63,11 @@ CONTAMINATION_GATED_TASKS = frozenset({
     "merge_pr",
     "delete_branch",
     "complete_issue",
+    # Web console recovery playbooks that write (#644). These mutate runtime
+    # binding and process state, so a live contamination marker must block them
+    # exactly as it blocks the Gitea-side mutations above. The reconciler
+    # cleanup playbook is the designated remedy and is exempted by its caller.
+    "console_recovery_apply",
 })
 
 CONTAMINATION_KIND = "stable_branch_push"