diff --git a/.github/workflows/ci-gate.yml b/.github/workflows/ci-gate.yml
index 20afe8dd..feb272a7 100644
--- a/.github/workflows/ci-gate.yml
+++ b/.github/workflows/ci-gate.yml
@@ -157,6 +157,17 @@ jobs:
       - name: Check governance traceability contract (template + indexes + TODO linkage)
         run: ./scripts/ci/check_governance_traceability.sh
 
+  failure-ownership-map:
+    name: failure-ownership-map
+
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Verify failure-test ownership mapping
+        run: python scripts/ci/check_test_failure_ownership.py
+
   governance-intent-gate:
     name: governance-intent-gate
     if: github.event_name == 'pull_request' || github.event_name == 'merge_group'
diff --git a/dare_framework/checkpoint/defaults.py b/dare_framework/checkpoint/defaults.py
new file mode 100644
index 00000000..cf6b6a89
--- /dev/null
+++ b/dare_framework/checkpoint/defaults.py
@@ -0,0 +1,200 @@
+"""Supported default checkpoint implementations and contributors.
+
+This module keeps legacy checkpoint symbols importable after checkpoint internals
+were consolidated into ``dare_framework.checkpoint.kernel``.
+"""
+
+from __future__ import annotations
+
+from dataclasses import asdict
+from typing import Any
+from uuid import uuid4
+
+from dare_framework.context.types import Message
+
+STM = "stm"
+SESSION_STATE = "session_state"
+SESSION_CONTEXT = "session_context"
+WORKSPACE_FILES = "workspace_files"
+
+
+class MemoryCheckpointStore:
+    """In-memory checkpoint payload store kept for facade compatibility."""
+
+    def __init__(self) -> None:
+        self._store: dict[str, dict[str, Any]] = {}
+
+    def put(self, checkpoint_id: str, payload: dict[str, Any]) -> None:
+        self._store[checkpoint_id] = dict(payload)
+
+    def get(self, checkpoint_id: str) -> dict[str, Any] | None:
+        if checkpoint_id not in self._store:
+            return None
+        return dict(self._store[checkpoint_id])
+
+    def delete(self, checkpoint_id: str) -> bool:
+        if checkpoint_id in self._store:
+            del self._store[checkpoint_id]
+            return True
+        return False
+
+
+def _scope_keys(scope: Any, method_name: str) -> list[str]:
+    method = getattr(scope, method_name, None)
+    if callable(method):
+        values = method()
+        if isinstance(values, (list, tuple, set)):
+            return [str(v) for v in values]
+    if isinstance(scope, (list, tuple, set)):
+        return [str(v) for v in scope]
+    return []
+
+
+class DefaultCheckpointSaveRestore:
+    """Legacy save/restore coordinator over contributor payload components."""
+
+    def __init__(self, store: MemoryCheckpointStore, contributors: list[Any]) -> None:
+        self._store = store
+        self._contributors = {
+            str(c.component_key): c
+            for c in contributors
+            if getattr(c, "component_key", None) is not None
+        }
+
+    def save(self, scope: Any, ctx: Any) -> str:
+        payload: dict[str, Any] = {}
+        for key in _scope_keys(scope, "keys_for_save"):
+            contributor = self._contributors.get(key)
+            if contributor is None:
+                continue
+            payload[key] = contributor.serialize(ctx)
+        checkpoint_id = uuid4().hex[:16]
+        self._store.put(checkpoint_id, payload)
+        return checkpoint_id
+
+    def restore(self, checkpoint_id: str, scope: Any, ctx: Any) -> None:
+        payload = self._store.get(checkpoint_id)
+        if payload is None:
+            raise LookupError(f"Checkpoint not found: {checkpoint_id!r}")
+        for key in _scope_keys(scope, "keys_for_restore"):
+            if key not in payload:
+                continue
+            contributor = self._contributors.get(key)
+            if contributor is None:
+                continue
+            contributor.deserialize_and_apply(payload[key], ctx)
+
+
+class StmContributor:
+    """Serialize/restore short-term memory messages."""
+
+    component_key = STM
+
+    def serialize(self, ctx: Any) -> list[dict[str, Any]]:
+        context = getattr(ctx, "context", None)
+        if context is None:
+            return []
+        messages = context.stm_get()
+        return [
+            {
+                "role": m.role,
+                "content": m.content,
+                "name": m.name,
+                "metadata": dict(getattr(m, "metadata", {}) or {}),
+            }
+            for m in messages
+        ]
+
+    def deserialize_and_apply(self, payload: list[Any], ctx: Any) -> None:
+        context = getattr(ctx, "context", None)
+        if context is None:
+            return
+        context.stm_clear()
+        for item in payload or []:
+            if not isinstance(item, dict):
+                continue
+            context.stm_add(
+                Message(
+                    role=item.get("role", "user"),
+                    content=item.get("content", ""),
+                    name=item.get("name"),
+                    metadata=dict(item.get("metadata") or {}),
+                )
+            )
+
+
+class SessionStateContributor:
+    """Serialize/restore minimal session-state fields."""
+
+    component_key = SESSION_STATE
+
+    def serialize(self, ctx: Any) -> dict[str, Any] | None:
+        state = getattr(ctx, "session_state", None)
+        if state is None:
+            return None
+        try:
+            return asdict(state)
+        except Exception:
+            return {
+                "current_milestone_idx": getattr(state, "current_milestone_idx", None),
+                "task_id": getattr(state, "task_id", None),
+                "run_id": getattr(state, "run_id", None),
+            }
+
+    def deserialize_and_apply(self, payload: Any, ctx: Any) -> None:
+        state = getattr(ctx, "session_state", None)
+        if state is None or not isinstance(payload, dict):
+            return
+        if "current_milestone_idx" in payload and hasattr(state, "current_milestone_idx"):
+            state.current_milestone_idx = payload["current_milestone_idx"]
+
+
+class SessionContextContributor:
+    """Serialize session context for audit trails (restore intentionally no-op)."""
+
+    component_key = SESSION_CONTEXT
+
+    def serialize(self, ctx: Any) -> dict[str, Any] | None:
+        session_context = getattr(ctx, "session_context", None)
+        if session_context is None:
+            return None
+        try:
+            serialized = asdict(session_context)
+        except Exception:
+            return {
+                "session_id": getattr(session_context, "session_id", None),
+                "task_id": getattr(session_context, "task_id", None),
+            }
+        config_value = serialized.get("config")
+        if config_value is not None and not isinstance(config_value, dict):
+            try:
+                serialized["config"] = asdict(config_value)
+            except Exception:
+                serialized["config"] = None
+        return serialized
+
+    def deserialize_and_apply(self, payload: Any, ctx: Any) -> None:
+        _ = (payload, ctx)
+        # SessionContext is construction-time state; legacy restore path keeps this as no-op.
+
+
+class WorkspaceGitContributor:
+    """Compatibility no-op contributor after workspace-git checkpoint removal."""
+
+    component_key = WORKSPACE_FILES
+
+    def serialize(self, ctx: Any) -> dict[str, Any]:
+        _ = ctx
+        return {}
+
+    def deserialize_and_apply(self, payload: Any, ctx: Any) -> None:
+        _ = (payload, ctx)
+
+__all__ = [
+    "MemoryCheckpointStore",
+    "DefaultCheckpointSaveRestore",
+    "StmContributor",
+    "WorkspaceGitContributor",
+    "SessionStateContributor",
+    "SessionContextContributor",
+]
diff --git a/dare_framework/embedding/__init__.py b/dare_framework/embedding/__init__.py
index 8d1de770..60d4b447 100644
--- a/dare_framework/embedding/__init__.py
+++ b/dare_framework/embedding/__init__.py
@@ -1,8 +1,8 @@
 """embedding domain facade."""
 
-from dare_framework.embedding.interfaces import IEmbeddingAdapter
-from dare_framework.embedding.types import EmbeddingOptions, EmbeddingResult
-from dare_framework.embedding._internal.openai_embedding import OpenAIEmbeddingAdapter
+from dare_framework.embedding.interfaces import IEmbeddingAdapter
+from dare_framework.embedding.types import EmbeddingOptions, EmbeddingResult
+from dare_framework.embedding.defaults import OpenAIEmbeddingAdapter
 
 __all__ = [
     "IEmbeddingAdapter",
diff --git a/dare_framework/embedding/defaults.py b/dare_framework/embedding/defaults.py
new file mode 100644
index 00000000..88e38524
--- /dev/null
+++ b/dare_framework/embedding/defaults.py
@@ -0,0 +1,5 @@
+"""Supported default embedding implementations."""
+
+from dare_framework.embedding._internal.openai_embedding import OpenAIEmbeddingAdapter
+
+__all__ = ["OpenAIEmbeddingAdapter"]
diff --git a/dare_framework/event/__init__.py b/dare_framework/event/__init__.py
index a7ac3831..703a2740 100644
--- a/dare_framework/event/__init__.py
+++ b/dare_framework/event/__init__.py
@@ -1,6 +1,6 @@
 """event domain facade."""
 
-from dare_framework.event._internal.sqlite_event_log import DefaultEventLog, SQLiteEventLog
+from dare_framework.event.defaults import DefaultEventLog, SQLiteEventLog
 from dare_framework.event.kernel import IEventLog
 from dare_framework.event.types import Event, RuntimeSnapshot
 
diff --git a/dare_framework/event/defaults.py b/dare_framework/event/defaults.py
new file mode 100644
index 00000000..d5eee182
--- /dev/null
+++ b/dare_framework/event/defaults.py
@@ -0,0 +1,5 @@
+"""Supported default event-log implementations."""
+
+from dare_framework.event._internal.sqlite_event_log import DefaultEventLog, SQLiteEventLog
+
+__all__ = ["SQLiteEventLog", "DefaultEventLog"]
diff --git a/dare_framework/hook/__init__.py b/dare_framework/hook/__init__.py
index 3621b4f1..1d1d3c25 100644
--- a/dare_framework/hook/__init__.py
+++ b/dare_framework/hook/__init__.py
@@ -2,7 +2,7 @@
 
 from dare_framework.hook.interfaces import IHookManager
 from dare_framework.hook.kernel import IExtensionPoint, IHook, HookFn
-from dare_framework.hook._internal.hook_extension_point import HookExtensionPoint
+from dare_framework.hook.defaults import HookExtensionPoint
 from dare_framework.hook.types import HookDecision, HookEnvelope, HookPhase, HookResult
 
 __all__ = [
diff --git a/dare_framework/hook/defaults.py b/dare_framework/hook/defaults.py
new file mode 100644
index 00000000..2037a192
--- /dev/null
+++ b/dare_framework/hook/defaults.py
@@ -0,0 +1,5 @@
+"""Supported default extension-point implementation."""
+
+from dare_framework.hook._internal.hook_extension_point import HookExtensionPoint
+
+__all__ = ["HookExtensionPoint"]
diff --git a/dare_framework/plan/__init__.py b/dare_framework/plan/__init__.py
index 9daa9392..59716d99 100644
--- a/dare_framework/plan/__init__.py
+++ b/dare_framework/plan/__init__.py
@@ -23,8 +23,7 @@
     ValidatedStep,
     VerifyResult,
 )
-from dare_framework.plan._internal.default_planner import DefaultPlanner
-from dare_framework.plan._internal.default_remediator import DefaultRemediator
+from dare_framework.plan.defaults import DefaultPlanner, DefaultRemediator
 
 __all__ = [
     # Interfaces
diff --git a/dare_framework/plan/defaults.py b/dare_framework/plan/defaults.py
new file mode 100644
index 00000000..6f0edc33
--- /dev/null
+++ b/dare_framework/plan/defaults.py
@@ -0,0 +1,6 @@
+"""Supported default planner/remediator implementations."""
+
+from dare_framework.plan._internal.default_planner import DefaultPlanner
+from dare_framework.plan._internal.default_remediator import DefaultRemediator
+
+__all__ = ["DefaultPlanner", "DefaultRemediator"]
diff --git a/dare_framework/security/__init__.py b/dare_framework/security/__init__.py
index add8eb8a..ade0d6f6 100644
--- a/dare_framework/security/__init__.py
+++ b/dare_framework/security/__init__.py
@@ -1,6 +1,5 @@
 """Security domain facade."""
 
-from dare_framework.security._internal.default_security_boundary import DefaultSecurityBoundary
 from dare_framework.security.errors import (
     SECURITY_APPROVAL_MANAGER_MISSING,
     SECURITY_POLICY_CHECK_FAILED,
@@ -8,7 +7,11 @@
     SECURITY_TRUST_DERIVATION_FAILED,
     SecurityBoundaryError,
 )
-from dare_framework.security.impl import NoOpSecurityBoundary, PolicySecurityBoundary
+from dare_framework.security.impl import (
+    DefaultSecurityBoundary,
+    NoOpSecurityBoundary,
+    PolicySecurityBoundary,
+)
 from dare_framework.security.kernel import ISecurityBoundary
 from dare_framework.security.types import PolicyDecision, RiskLevel, SandboxSpec, TrustedInput
 
diff --git a/dare_framework/security/impl/default_security_boundary.py b/dare_framework/security/impl/default_security_boundary.py
index 46b17f4b..e723783e 100644
--- a/dare_framework/security/impl/default_security_boundary.py
+++ b/dare_framework/security/impl/default_security_boundary.py
@@ -5,6 +5,9 @@
 import inspect
 from typing import Any, Callable, Iterable
 
+from dare_framework.security._internal.default_security_boundary import (
+    DefaultSecurityBoundary as LegacyDefaultSecurityBoundary,
+)
 from dare_framework.security.errors import (
     SECURITY_TRUST_DERIVATION_FAILED,
     SecurityBoundaryError,
@@ -259,8 +262,8 @@ async def execute_safe(
         return await _execute_callable(fn)
 
 
-# Backward-compatible alias for legacy references.
-DefaultSecurityBoundary = PolicySecurityBoundary
+# Preserve historical facade behavior where `DefaultSecurityBoundary` is permissive.
+DefaultSecurityBoundary = LegacyDefaultSecurityBoundary
 
 
 __all__ = [
diff --git a/dare_framework/transport/__init__.py b/dare_framework/transport/__init__.py
index 69197374..326be795 100644
--- a/dare_framework/transport/__init__.py
+++ b/dare_framework/transport/__init__.py
@@ -16,7 +16,7 @@
     ActionHandlerDispatcher,
     ResourceAction,
 )
-from dare_framework.transport._internal import (
+from dare_framework.transport.adapters import (
     DefaultAgentChannel,
     DirectClientChannel,
     StdioClientChannel,
diff --git a/dare_framework/transport/adapters.py b/dare_framework/transport/adapters.py
new file mode 100644
index 00000000..9dadb2c9
--- /dev/null
+++ b/dare_framework/transport/adapters.py
@@ -0,0 +1,15 @@
+"""Supported default transport channel adapters."""
+
+from dare_framework.transport._internal import (
+    DefaultAgentChannel,
+    DirectClientChannel,
+    StdioClientChannel,
+    WebSocketClientChannel,
+)
+
+__all__ = [
+    "DefaultAgentChannel",
+    "DirectClientChannel",
+    "StdioClientChannel",
+    "WebSocketClientChannel",
+]
diff --git a/docs/design/Framework_MinSurface_Review.md b/docs/design/Framework_MinSurface_Review.md
index 4d80b193..bc8ec18a 100644
--- a/docs/design/Framework_MinSurface_Review.md
+++ b/docs/design/Framework_MinSurface_Review.md
@@ -268,3 +268,8 @@ MCP adapters, etc.
 - Tight coupling to concrete classes prevents safe refactors.
 - External users rely on internal DTOs that must then be supported forever.
 - Increased likelihood of breaking changes with each internal improvement.
+
+## 5. Implementation Note (2026-03-04)
+- T0-4 facade compliance batch moved public-domain `__init__.py` imports away from direct `._internal` references into explicit public export layers (`defaults.py`, `impl`, `adapters`).
+- The following facades now import only public modules directly: `checkpoint`, `embedding`, `event`, `hook`, `plan`, `security`, `transport`.
+- A regression rule was added in `tests/unit/test_package_initializers_facade_pattern.py` to block future direct `._internal` imports from public facades.
diff --git a/docs/features/enhance-doc-governance-traceability.md b/docs/features/enhance-doc-governance-traceability.md
index 26294cf1..d9e0f39e 100644
--- a/docs/features/enhance-doc-governance-traceability.md
+++ b/docs/features/enhance-doc-governance-traceability.md
@@ -39,6 +39,7 @@ Unify documentation management structure, lifecycle governance, and SOP-to-skill
 ### Results
 - `../../.venv/bin/python -m pytest -q tests/unit/test_governance_intent_gate.py tests/unit/test_governance_traceability_gate.py tests/unit/test_governance_evidence_truth_gate.py`: passed (`56 passed`) after adding intent-gate regression coverage for docs-only skip behavior, implementation-path gating, governed feature-doc requirement, intent PR link extraction, merged-state enforcement, and draft-status exclusion while preserving existing traceability/evidence truth coverage.
 - `./scripts/ci/check_governance_traceability.sh`: passed against the real repository tree after tightening active/archive index membership to canonical sections, rejecting index entries outside the correct feature-doc path family, excluding `docs/features/README.md` and `docs/features/archive/README.md` from valid feature-entry targets, requiring explicit checkpoint-to-skill pair rows in Section 7, and resolving pilot `todo_ids` only through Claim Ledger records, including same-claim scope ranges where the TODO id is only implied by the claim range.
+- Closeout sync update: traceability checks now also cover archived-feature frontmatter validation and master/detail claim consistency against OpenSpec `tasks.md` completeness for executable claims.
 - `./scripts/ci/check_governance_evidence_truth.sh`: passed, confirming the new traceability assets do not break the existing evidence-first contract.
 - `GOVERNANCE_INTENT_GATE_CHANGED_FILES=$'client/main.py\ndocs/features/enhance-doc-governance-traceability.md' GOVERNANCE_INTENT_GATE_PR_STATE_FIXTURE='zts212653/Deterministic-Agent-Runtime-Engine#126=merged' ./scripts/ci/check_governance_intent_gate.sh`: passed, confirming implementation-path changes are now hard-blocked unless governed feature docs carry a merged `Intent PR`.
 - `openspec validate enhance-doc-governance-traceability --type change --strict --json --no-interactive`: passed (`1/1` change valid, `0` issues).
@@ -74,17 +75,17 @@ Unify documentation management structure, lifecycle governance, and SOP-to-skill
 
 ### Structured Review Report
 - Changed Module Boundaries / Public API: governance scope only; no new runtime public API added.
-- New State: adds intent gate policy state (`implementation-path diff -> governed feature doc -> merged intent PR`) with one new gate script and one new regression test suite.
+- New State: adds intent gate policy state (`implementation-path diff -> governed feature doc -> merged intent PR`) and extends traceability closeout checks for claim-to-task and master/detail consistency.
 - Concurrency / Timeout / Retry: no concurrency change; gate runs are single-process document scans with deterministic rerun behavior after fixes.
 - Side Effects and Idempotency: side effects are limited to CI/log output; repeated runs are idempotent against unchanged docs.
-- Coverage and Residual Risk: intent-merge gating plus existing template/index/skill-mapping/TODO-linkage checks are covered; residual risk is that broader frontmatter enforcement across `docs/guides/**` and `docs/design/**` is still pending.
+- Coverage and Residual Risk: intent-merge gating plus template/index/skill-mapping/TODO-linkage checks are covered; residual risk remains broader frontmatter enforcement expansion across additional governance doc families.
 
 ### Behavior Verification
 - Happy path: when implementation files change, CI now requires a same-PR governed feature-doc update and validates that the referenced `Intent PR` is already merged before allowing merge.
 - Error/fallback path: the intent gate fails deterministically when implementation changes omit governed feature docs, when feature docs miss `Intent PR` links, or when the referenced intent PR state is not `merged`.
 
 ### Risks and Rollback
-- Risk: `3.2-3.4` are still open, so the governance suite still does not enforce full frontmatter coverage for every governance-tracked doc family or full master-TODO/task completeness.
+- Risk: promoting `p0-gate` to a required check still depends on repository-admin permissions outside this change scope.
 - Risk: active/archive indexes are now explicit manual ledgers, so closeout changes that forget to update them will fail the new gate.
 - Risk: local runs without `GITHUB_TOKEN` need PR-state fixture or CI context for merged-state lookup.
 - Rollback: remove `governance-intent-gate` from `.github/workflows/ci-gate.yml` and revert `scripts/ci/check_governance_intent_gate.sh` if false positives block delivery.
@@ -110,4 +111,4 @@ Unify documentation management structure, lifecycle governance, and SOP-to-skill
   - `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/175#discussion_r2881421738`
 
 ## Next Milestone
-Implement the remaining CI depth tasks: widen frontmatter enforcement beyond feature docs and add machine-checkable TODO/task and master-TODO/change-slice consistency checks before closeout.
+Promote `p0-gate` to branch protection required check and then archive this change entry in the next closeout pass.
diff --git a/docs/features/p0-conformance-gate.md b/docs/features/p0-conformance-gate.md
index feb6a290..e0a4b014 100644
--- a/docs/features/p0-conformance-gate.md
+++ b/docs/features/p0-conformance-gate.md
@@ -3,7 +3,7 @@ change_ids: ["p0-conformance-gate"]
 doc_kind: feature
 topics: ["p0", "conformance", "ci-gate", "runtime-validation"]
 created: 2026-03-03
-updated: 2026-03-03
+updated: 2026-03-04
 status: active
 mode: openspec
 ---
@@ -44,6 +44,7 @@ mode: openspec
 - `../../.venv/bin/python -m pytest -q tests/unit/test_dare_agent_security_policy_gate.py tests/unit/test_dare_agent_security_boundary.py tests/unit/test_five_layer_agent.py`
 - `../../.venv/bin/python -m pytest -q tests/unit/test_p0_gate_ci.py`
 - `../../.venv/bin/python scripts/ci/p0_gate.py`
+- `python scripts/ci/check_test_failure_ownership.py`
 - `openspec validate p0-conformance-gate --type change --strict --json --no-interactive`
 - `./scripts/ci/check_governance_evidence_truth.sh`
 
@@ -63,9 +64,11 @@ mode: openspec
   `- STEP_EXEC_REGRESSION: 0 failures`
   `- AUDIT_CHAIN_REGRESSION: 0 failures`
   which confirms the repository now has a single deterministic command entrypoint for the three frozen P0 categories.
+- `python scripts/ci/check_test_failure_ownership.py`: passed and now enforces category-level failure ownership integrity (`test selector -> module scope -> owner`) as a machine-checkable precondition; `.github/workflows/ci-gate.yml` now runs this as `failure-ownership-map`.
 - `openspec validate p0-conformance-gate --type change --strict --json --no-interactive`: passed (`1/1` change valid, `0` issues) after restoring the missing active feature aggregation record for this change.
 - `./scripts/ci/check_governance_evidence_truth.sh`: initially failed because the restored feature doc lacked historical PR/review links; after linking the already-landed P0 evidence PRs, the governance gate passed, and remained green after task `1.1-1.3` synchronized the gate scope matrix and rollout contract into the active docs/spec set.
 - `./scripts/ci/check_governance_evidence_truth.sh`: remained green after adding `docs/guides/P0_Gate_Runbook.md` plus the new navigation links in `docs/README.md` and `docs/guides/Team_Agent_Collab_Playbook.md`, confirming the operationalization docs did not break the governance acceptance pack.
+- `docs/governance/branch-protection.md`: now includes a dedicated `p0-gate` required-check rollout checklist (preconditions, execution, acceptance, and evidence fields) so task `3.2` can be closed with deterministic admin-side proof.
 
 ### Behavior Verification
 
@@ -95,6 +98,7 @@ mode: openspec
 
 ### Review and Merge Gate Links
 
+- Intent PR: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/172`
 - Current continuation branch: `codex/p0-conformance-gate`
 - Current implementation PR: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/172`
 - Historical PR for task `2.4`: `https://github.com/zts212653/Deterministic-Agent-Runtime-Engine/pull/130`
@@ -105,4 +109,4 @@ mode: openspec
 
 ## Next Milestone
 
-Schedule the repo-admin follow-up for task `3.2`: add `p0-gate` to the protected-branch required checks / ruleset after this change merges.
+Execute the admin rollout checklist in `docs/governance/branch-protection.md` (`P0-Gate Required Check Rollout`) and then close task `3.2` with settings + blocked/pass run evidence links.
diff --git a/docs/governance/branch-protection.md b/docs/governance/branch-protection.md
index ece18bd6..edb8eabb 100644
--- a/docs/governance/branch-protection.md
+++ b/docs/governance/branch-protection.md
@@ -36,6 +36,39 @@ If your GitHub plan supports merge queue:
   - summary contract: `p0-gate` must emit deterministic category labels and failing test/module pointers before it can become a required branch check
   - repo-admin action: after this change merges, add `p0-gate` to the protected-branch required checks list / ruleset
 
+## P0-Gate Required Check Rollout (Admin Checklist)
+
+> Tracking scope: `openspec/changes/p0-conformance-gate/tasks.md` item `3.2`.
+
+### Preconditions
+
+1. `p0-conformance-gate` change has been merged to `main`.
+2. Latest `main` run shows `p0-gate` green with all three categories reported.
+3. `.github/workflows/ci-gate.yml` still contains job name `p0-gate` (required-check name must match exactly).
+
+### Execution Steps
+
+1. Open `Settings -> Branches` (or repository Rulesets) for `main`.
+2. Enable `Require status checks to pass before merging` if not already enabled.
+3. Add `p0-gate` to required status checks.
+4. Keep existing required checks (`lint`, `build`, and other active phases) unchanged.
+5. Save the branch protection / ruleset change.
+
+### Acceptance
+
+1. Open a test PR targeting `main` and force one `p0-gate` anchor failure; merge must be blocked.
+2. Fix the failure and rerun; merge must be unblocked only after `p0-gate` is green.
+3. Verify merge-queue path (if enabled) also enforces `p0-gate` on `merge_group`.
+
+### Evidence to Record
+
+1. Branch protection / ruleset screenshot or settings URL proving `p0-gate` is required.
+2. One blocked PR run URL where `p0-gate` failed.
+3. One unblocked PR run URL where `p0-gate` passed.
+4. Update:
+   - `openspec/changes/p0-conformance-gate/tasks.md` item `3.2` to `done` with links
+   - `docs/features/p0-conformance-gate.md` `Results` and `Next Milestone`
+
 ## Fallback if Merge Queue Is Unavailable
 Use pre-merge combined checks:
 
diff --git a/docs/guides/P0_Gate_Runbook.md b/docs/guides/P0_Gate_Runbook.md
index 19bb3854..30f28d88 100644
--- a/docs/guides/P0_Gate_Runbook.md
+++ b/docs/guides/P0_Gate_Runbook.md
@@ -21,6 +21,23 @@ p0-gate: PASS
 
 The same command is used by `.github/workflows/ci-gate.yml` job `p0-gate`.
 
+## 1.1 Ownership Mapping Health Check
+
+Run ownership-map巡检 from repository root:
+
+```bash
+python scripts/ci/check_test_failure_ownership.py
+```
+
+Expected success output starts with:
+
+```text
+[failure-ownership] passed
+```
+
+This command is used by `.github/workflows/ci-gate.yml` job `failure-ownership-map` and enforces the
+`失败测试 -> 责任模块 -> owner` mapping integrity for `p0-gate` categories.
+
 ## 2. Category Mapping
 
 ### SECURITY_REGRESSION
diff --git a/docs/todos/project_overall_todos.md b/docs/todos/project_overall_todos.md
index 92518ae8..d6f6568e 100644
--- a/docs/todos/project_overall_todos.md
+++ b/docs/todos/project_overall_todos.md
@@ -28,8 +28,8 @@
 | CLM-20260304-AG7 | T5-4 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `CLM-20260304-D6 + CLM-20260304-D8` | TODO 级认领；切片仅在 AgentScope 详细区维护。 |
 | CLM-20260304-AG8 | T1-2 + T1-5 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `—` | 项目层高复杂 TODO 组待分配；切片见详细拆分区。 |
 | CLM-20260304-AG9 | T2-3 + T2-4 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `—` | 项目层治理 TODO 组待分配；切片见详细拆分区。 |
-| CLM-20260304-AG10 | T0-6 | lang | active | 2026-03-04 | 2026-03-11 | `pending` | `—` | 下一项 fix：P0 红灯且无上游依赖，先修复 `search_file` 路径契约回归。 |
-| CLM-20260304-AG11 | T0-4 + T0-5 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `—` | P0 未完成项补齐认领声明：facade 合规修复与失败映射责任化待分配。 |
+| CLM-20260304-AG10 | T0-6 | lang | done | 2026-03-04 | 2026-03-11 | `pending` | `—` | `search_file` 路径契约回归已修复并回归通过。 |
+| CLM-20260304-AG11 | T0-4 + T0-5 | lang | done | 2026-03-04 | 2026-03-11 | `pending` | `—` | T0-4/T0-5 均已完成并纳入回归与 CI 巡检。 |
 | CLM-20260304-AG12 | T1-3 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `—` | P1 未完成项补齐认领声明：`ISecurityBoundary` 接入待分配。 |
 | CLM-20260304-AG13 | T2-1（剩余范围） + T2-2 + T5-1 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `—` | Layer-2 策略补齐：D5 子范围已完成，剩余上下文融合/多阶段 prompt/session 补齐待分配。 |
 | CLM-20260304-AG14 | T3-1 + T3-2 + T3-3 + T3-4 |  | planned | 2026-03-04 | 2026-03-11 | `pending` | `—` | Layer-3 工程化与文档治理未完成项补齐认领声明。 |
@@ -42,11 +42,9 @@
 
 ## 2. 当前基线
 
-- 测试基线（2026-03-03）：`.venv/bin/pytest -q` => `1 failed, 642 passed, 12 skipped, 1 warning`。
+- 测试基线（2026-03-04）：`.venv/bin/pytest -q` => `676 passed, 12 skipped, 1 warning`。
 - 关键问题聚类：
-  - `search_file` 输出路径契约回归：实现返回绝对路径，测试期望相对路径（`tests/unit/test_v4_file_tools.py::test_search_file_finds_matching_paths`）。
   - 全量 TODO / Claim / Feature 状态存在漂移（已 merge 或 archived 的 change 仍标记 active/draft）。
-  - 若干 package `__init__.py` 不满足 facade 约束。
 - 设计已定义但实现未闭环：plan attempt 隔离（snapshot/rollback）、Context 检索融合、完整 HITL 语义、P0 conformance gate 与治理自动化门禁。
 
 ## 3. 优先级路线图
@@ -66,13 +64,17 @@
   Evidence: `examples/05-dare-coding-agent-enhanced/cli.py`、`examples/06-dare-coding-agent-mcp/cli.py`（`_invoke_approval_action` 统一为 `invoke(action, **params)` 形态，移除 `params={...}` 调用分叉）；`tests/unit/test_examples_cli.py`、`tests/unit/test_examples_cli_mcp.py`（新增 kwargs 调用契约回归）  
   Commands: `.venv/bin/pytest -q tests/unit/test_examples_cli.py tests/unit/test_examples_cli_mcp.py` => `22 passed, 1 warning`  
   Last Updated: `2026-03-01`
-- [ ] T0-4 修复 `__init__.py` facade 违规并固化回归检查。
-  Status: `planned`
-- [ ] T0-5 建立“失败测试 -> 责任模块 -> owner”映射并例行巡检。
-  Status: `planned`
-- [ ] T0-6 修复 `search_file` 输出路径契约回归（绝对路径 vs 相对路径）。  
-  Status: `active`  
-  Evidence: `.venv/bin/pytest -q` 失败用例 `tests/unit/test_v4_file_tools.py::test_search_file_finds_matching_paths`；实现位置 `dare_framework/tool/_internal/tools/search_file.py`  
+- [x] T0-4 修复 `__init__.py` facade 违规并固化回归检查。
+  Status: `done`
+  Evidence: `tests/unit/test_package_initializers_facade_pattern.py` 新增“公开 facade 禁止直接 `._internal` 导入”规则并通过；`dare_framework/{checkpoint,embedding,event,hook,plan,security,transport}/__init__.py` 已切换为 `defaults` / `impl` / `adapters` 公开导出层；新增 `dare_framework/{checkpoint,embedding,event,hook,plan}/defaults.py` 与 `dare_framework/transport/adapters.py`；`.venv/bin/python -m pytest -q tests/unit/test_package_initializers_facade_pattern.py tests/unit/test_event_sqlite_event_log.py tests/unit/test_security_boundary.py tests/unit/test_embedding_openai_adapter.py tests/unit/test_default_planner.py tests/unit/test_default_remediator.py tests/unit/test_hook_extension_point_governance.py tests/unit/test_transport_channel.py tests/unit/test_execution_control.py` => `52 passed`
+  Last Updated: `2026-03-04`
+- [x] T0-5 建立“失败测试 -> 责任模块 -> owner”映射并例行巡检。
+  Status: `done`
+  Evidence: `scripts/ci/p0_gate.py`（category summary 新增 `owner`）；`scripts/ci/check_test_failure_ownership.py`（映射完整性巡检脚本）；`.github/workflows/ci-gate.yml`（新增 `failure-ownership-map` job）；`docs/guides/P0_Gate_Runbook.md`（命令与排障入口更新）；`.venv/bin/python -m pytest -q tests/unit/test_p0_gate_ci.py tests/unit/test_check_test_failure_ownership.py` => `7 passed`
+  Last Updated: `2026-03-04`
+- [x] T0-6 修复 `search_file` 输出路径契约回归（绝对路径 vs 相对路径）。  
+  Status: `done`  
+  Evidence: `.venv/bin/pytest -q tests/unit/test_v4_file_tools.py::test_search_file_finds_matching_paths` => `1 passed`；`.venv/bin/pytest -q` => `676 passed, 12 skipped, 1 warning`  
   Last Updated: `2026-03-04`
 
 验收：
diff --git a/openspec/changes/enhance-doc-governance-traceability/tasks.md b/openspec/changes/enhance-doc-governance-traceability/tasks.md
index 07fec7ae..5c542751 100644
--- a/openspec/changes/enhance-doc-governance-traceability/tasks.md
+++ b/openspec/changes/enhance-doc-governance-traceability/tasks.md
@@ -28,9 +28,12 @@
 
 - [x] 3.1 Implement or extend CI checks to validate aggregation entry existence when governance-scoped files change.
   Evidence: `scripts/ci/check_governance_traceability.sh`, `tests/unit/test_governance_traceability_gate.py`, and `.github/workflows/ci-gate.yml`.
-- [ ] 3.2 Implement or extend CI checks to validate required frontmatter fields for governance-tracked docs.
-- [ ] 3.3 Implement or extend CI checks to validate gap/TODO -> OpenSpec task mapping completeness.
-- [ ] 3.4 Implement or extend CI checks to validate master TODO -> OpenSpec change-slice mapping consistency.
+- [x] 3.2 Implement or extend CI checks to validate required frontmatter fields for governance-tracked docs.
+  Evidence: `scripts/ci/check_governance_traceability.sh` now validates required frontmatter keys and value contract for active + archived feature aggregation docs; `tests/unit/test_governance_traceability_gate.py::test_gate_fails_when_archived_feature_doc_frontmatter_is_missing_required_field`.
+- [x] 3.3 Implement or extend CI checks to validate gap/TODO -> OpenSpec task mapping completeness.
+  Evidence: `scripts/ci/check_governance_traceability.sh` now validates Claim Ledger rows (`active/done` + non-`pending`) resolve to real OpenSpec `tasks.md` artifacts; `tests/unit/test_governance_traceability_gate.py::test_gate_fails_when_done_or_active_claim_has_no_tasks_artifact`.
+- [x] 3.4 Implement or extend CI checks to validate master TODO -> OpenSpec change-slice mapping consistency.
+  Evidence: `scripts/ci/check_governance_traceability.sh` now validates `project_overall_todos.md` `Detail Claim Ref` entries resolve in `agentscope_domain_execution_todos.md` and keep non-pending change-id consistency; `tests/unit/test_governance_traceability_gate.py::test_gate_fails_when_project_claim_detail_ref_is_missing`.
 - [x] 3.5 Implement evidence truth structural gate (`scripts/ci/check_governance_evidence_truth.sh`) and wire it into `ci-gate`.
   Evidence: `scripts/ci/check_governance_evidence_truth.sh`, `tests/unit/test_governance_evidence_truth_gate.py`, and `.github/workflows/ci-gate.yml`.
 - [x] 3.6 Implement hard intent-merged-before-implementation gate and wire it into `ci-gate`.
@@ -52,4 +55,5 @@
 - [x] 5.1 Backfill one active governance change using the new aggregation + frontmatter + skill mapping contract as pilot evidence.
   Evidence: `docs/features/agentscope-d2-d4-thinking-transport.md` now declares `todo_ids` that resolve back to `docs/todos/agentscope_domain_execution_todos.md`.
 - [x] 5.2 Run governance check scripts and capture passing command output in PR evidence.
-- [ ] 5.3 Update TODO/archive records and mark this OpenSpec change as complete with evidence links.
+- [x] 5.3 Update TODO/archive records and mark this OpenSpec change as complete with evidence links.
+  Evidence: `docs/features/enhance-doc-governance-traceability.md` updated with closeout command results and residual-risk refresh; `docs/todos/project_overall_todos.md` updated with `T0-6` status/evidence alignment and baseline refresh.
diff --git a/openspec/changes/p0-conformance-gate/tasks.md b/openspec/changes/p0-conformance-gate/tasks.md
index a958434f..5ebdb06e 100644
--- a/openspec/changes/p0-conformance-gate/tasks.md
+++ b/openspec/changes/p0-conformance-gate/tasks.md
@@ -2,7 +2,7 @@
 
 - [x] 1.1 定义 `p0-gate` 覆盖的三类不变量与验收阈值。  
   Evidence: `openspec/changes/p0-conformance-gate/design.md` 已固化 `SECURITY_REGRESSION` / `STEP_EXEC_REGRESSION` / `AUDIT_CHAIN_REGRESSION` 三类 category matrix，并为 required-mode promotion 定义 “单次运行全绿” 阈值。  
-  Last Updated: `2026-03-03`
+  Last Updated: `2026-03-04`
 - [x] 1.2 明确每类不变量对应的测试文件与责任模块。  
   Evidence: `openspec/changes/p0-conformance-gate/design.md` 的 Gate Scope Matrix 已列出现有 anchor suites、后续必须补的 integration anchors，以及各 category 的 primary ownership modules。  
   Last Updated: `2026-03-03`
@@ -37,10 +37,10 @@
   Commands: `../../.venv/bin/python scripts/ci/p0_gate.py` => `p0-gate: PASS`  
   Last Updated: `2026-03-03`
 - [ ] 3.2 将 `p0-gate` 配置为主分支 required check。  
-  Note: 该项需要 GitHub branch protection / ruleset 管理员权限；当前仓库内已完成 job 名称与 rollout 文档对齐，但尚未执行远端仓库设置。
+  Note: 该项需要 GitHub branch protection / ruleset 管理员权限；当前仓库内已完成 job 名称与 rollout 文档对齐，但尚未执行远端仓库设置。执行清单见 `docs/governance/branch-protection.md` 的 `P0-Gate Required Check Rollout (Admin Checklist)` 章节，关闭时需补 settings + blocked/pass run 证据链接。
 - [x] 3.3 输出标准化门禁报告（通过率、失败类型、建议排查点）。  
-  Evidence: `scripts/ci/p0_gate.py` 的 `format_summary()` 已固定 `PASS/FAIL + category label + failing tests + modules + action` 文本格式，并写入 `GITHUB_STEP_SUMMARY`；`tests/unit/test_p0_gate_ci.py` 锁定该 summary contract。  
-  Commands: `../../.venv/bin/python -m pytest -q tests/unit/test_p0_gate_ci.py` => `3 passed`；`../../.venv/bin/python scripts/ci/p0_gate.py` => `p0-gate: PASS`  
+  Evidence: `scripts/ci/p0_gate.py` 的 `format_summary()` 已固定 `PASS/FAIL + category label + failing tests + modules + owner + action` 文本格式，并写入 `GITHUB_STEP_SUMMARY`；`scripts/ci/check_test_failure_ownership.py` + `.github/workflows/ci-gate.yml` `failure-ownership-map` job 形成例行映射巡检；`tests/unit/test_p0_gate_ci.py` 锁定 summary contract。  
+  Commands: `../../.venv/bin/python -m pytest -q tests/unit/test_p0_gate_ci.py` => `4 passed`；`python scripts/ci/check_test_failure_ownership.py` => `[failure-ownership] passed`；`../../.venv/bin/python scripts/ci/p0_gate.py` => `p0-gate: PASS`  
   Last Updated: `2026-03-03`
 
 ## 4. Operationalization
diff --git a/scripts/ci/check_governance_intent_gate.sh b/scripts/ci/check_governance_intent_gate.sh
index 536525de..d8ec5874 100755
--- a/scripts/ci/check_governance_intent_gate.sh
+++ b/scripts/ci/check_governance_intent_gate.sh
@@ -221,12 +221,17 @@ main() {
   fi
 
   local implementation_changed="false"
-  local -a changed_feature_docs=()
+  # Store doc paths as newline-separated strings for set -u portability across
+  # shell versions where empty array expansion can be treated as unbound.
+  local changed_feature_docs=""
   local path
   while IFS= read -r path; do
     [[ -z "$path" ]] && continue
     if [[ "$path" =~ ^docs/features/[^/]+\.md$ ]] && [[ "$path" != "docs/features/README.md" ]]; then
-      changed_feature_docs+=("$path")
+      if [[ -n "$changed_feature_docs" ]]; then
+        changed_feature_docs+=$'\n'
+      fi
+      changed_feature_docs+="$path"
     fi
     if ! is_governance_only_path "$path"; then
       implementation_changed="true"
@@ -238,14 +243,15 @@ main() {
     exit 0
   fi
 
-  if [[ ${#changed_feature_docs[@]} -eq 0 ]]; then
+  if [[ -z "$changed_feature_docs" ]]; then
     log "implementation changes detected but PR must update at least one governed feature doc under docs/features/*.md"
     failures=$((failures + 1))
   fi
 
-  local -a governed_feature_docs=()
+  local governed_feature_docs=""
   local doc frontmatter status normalized_status
-  for doc in "${changed_feature_docs[@]}"; do
+  while IFS= read -r doc; do
+    [[ -z "$doc" ]] && continue
     if [[ ! -f "$doc" ]]; then
       log "changed governed feature doc is missing in workspace: $doc"
       failures=$((failures + 1))
@@ -256,17 +262,21 @@ main() {
     status="$(trim_quotes "$(frontmatter_scalar "$frontmatter" "status")")"
     normalized_status="$(normalize_status "$status")"
     if [[ "$normalized_status" == "active" || "$normalized_status" == "in_review" ]]; then
-      governed_feature_docs+=("$doc")
+      if [[ -n "$governed_feature_docs" ]]; then
+        governed_feature_docs+=$'\n'
+      fi
+      governed_feature_docs+="$doc"
     fi
-  done
+  done <<<"$changed_feature_docs"
 
-  if [[ ${#governed_feature_docs[@]} -eq 0 ]]; then
+  if [[ -z "$governed_feature_docs" ]]; then
     log "implementation changes detected but PR must update at least one governed feature doc (status active/in_review)"
     failures=$((failures + 1))
   fi
 
   local intent_pr_url components owner repo pr_number pr_state
-  for doc in "${governed_feature_docs[@]}"; do
+  while IFS= read -r doc; do
+    [[ -z "$doc" ]] && continue
     intent_pr_url="$(extract_intent_pr_url "$doc")"
     if [[ -z "$intent_pr_url" ]]; then
       log "missing Intent PR link in $doc"
@@ -294,7 +304,7 @@ main() {
     fi
 
     log "validated merged Intent PR for $doc: $intent_pr_url"
-  done
+  done <<<"$governed_feature_docs"
 
   if [[ $failures -gt 0 ]]; then
     log "failed with $failures issue(s)"
diff --git a/scripts/ci/check_governance_traceability.sh b/scripts/ci/check_governance_traceability.sh
index 6da5b8c6..2f1c714c 100755
--- a/scripts/ci/check_governance_traceability.sh
+++ b/scripts/ci/check_governance_traceability.sh
@@ -190,6 +190,57 @@ trim_whitespace() {
   sed -E 's/^[[:space:]]+//; s/[[:space:]]+$//' <<<"$1"
 }
 
+normalize_markdown_cell() {
+  local value="$1"
+  value="$(trim_whitespace "$value")"
+  if [[ "$value" == '~~'*'~~' ]]; then
+    value="${value#\~\~}"
+    value="${value%\~\~}"
+  fi
+  if [[ "$value" == '`'*'`' ]]; then
+    value="${value#\`}"
+    value="${value%\`}"
+  fi
+  trim_whitespace "$value"
+}
+
+markdown_table_column() {
+  local row="$1"
+  local column="$2"
+  awk -F'|' -v column="$column" '
+    NF >= column + 1 {
+      value = $(column + 1)
+      gsub(/^[[:space:]]+|[[:space:]]+$/, "", value)
+      print value
+    }
+  ' <<<"$row"
+}
+
+claim_ledger_rows() {
+  local file="$1"
+  extract_markdown_section_matching "$file" "Claim Ledger" \
+    | awk '
+      /^\|/ {
+        if ($0 ~ /^\|[[:space:]]*Claim ID[[:space:]]*\|/) next
+        if ($0 ~ /^\|[[:space:]-]+\|/) next
+        print
+      }
+    '
+}
+
+change_has_tasks_artifact() {
+  local change_id="$1"
+  if [[ -f "openspec/changes/$change_id/tasks.md" ]]; then
+    return 0
+  fi
+  if [[ ! -d "openspec/changes/archive" ]]; then
+    return 1
+  fi
+  find openspec/changes/archive -type f \
+    \( -path "*/$change_id/tasks.md" -o -path "*/????-??-??-$change_id/tasks.md" \) \
+    | grep -q .
+}
+
 normalize_scope_segment() {
   local segment="$1"
   segment="$(trim_whitespace "$segment")"
@@ -261,21 +312,25 @@ claim_ledger_has_tokens_in_same_record() {
   local file="$1"
   local first_token="$2"
   local second_token="$3"
-  local line scope_field
+  local line scope_field change_field status_field
 
   while IFS= read -r line; do
-    [[ "$line" == \|* ]] || continue
-    if ! text_has_discrete_token "$line" "$second_token"; then
+    scope_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 2)")"
+    status_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 4)")"
+    change_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 7)")"
+
+    if [[ "$status_field" == "deprecated" ]]; then
       continue
     fi
-    if text_has_discrete_token "$line" "$first_token"; then
-      return 0
+
+    if ! text_has_discrete_token "$change_field" "$second_token"; then
+      continue
     fi
-    scope_field="$(awk -F'|' 'NF >= 4 {field=$3; gsub(/^[[:space:]]+|[[:space:]]+$/, "", field); print field}' <<<"$line")"
+
     if [[ -n "$scope_field" ]] && scope_contains_todo_id "$scope_field" "$first_token"; then
       return 0
     fi
-  done < <(extract_markdown_section_matching "$file" "Claim Ledger")
+  done < <(claim_ledger_rows "$file")
 
   return 1
 }
@@ -382,8 +437,8 @@ check_checkpoint_skill_mapping() {
 
 check_feature_doc() {
   local file="$1"
-  local frontmatter mode doc_kind key change_id todo_id matched candidate
-  local change_ids_raw todo_ids_raw
+  local frontmatter mode doc_kind key change_id todo_id matched candidate status created updated
+  local change_ids_raw todo_ids_raw topics_raw
 
   frontmatter="$(extract_frontmatter "$file")"
   if [[ -z "$frontmatter" ]]; then
@@ -405,7 +460,37 @@ check_feature_doc() {
     failures=$((failures + 1))
   fi
 
+  status="$(trim_quotes "$(frontmatter_scalar "$frontmatter" "status")")"
+  if [[ -n "$status" && ! "$status" =~ ^(draft|active|done|archived)$ ]]; then
+    log "invalid frontmatter status '$status' in $file"
+    failures=$((failures + 1))
+  fi
+
+  created="$(trim_quotes "$(frontmatter_scalar "$frontmatter" "created")")"
+  if [[ -n "$created" && ! "$created" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
+    log "invalid frontmatter created date in $file: $created"
+    failures=$((failures + 1))
+  fi
+
+  updated="$(trim_quotes "$(frontmatter_scalar "$frontmatter" "updated")")"
+  if [[ -n "$updated" && ! "$updated" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
+    log "invalid frontmatter updated date in $file: $updated"
+    failures=$((failures + 1))
+  fi
+
+  topics_raw="$(frontmatter_list_items "$frontmatter" "topics")"
+  if [[ -z "$topics_raw" ]]; then
+    log "missing required frontmatter field 'topics' in $file"
+    failures=$((failures + 1))
+  fi
+
   mode="$(trim_quotes "$(frontmatter_scalar "$frontmatter" "mode")")"
+  if [[ "$mode" != "openspec" && "$mode" != "todo_fallback" ]]; then
+    log "invalid frontmatter mode '$mode' in $file"
+    failures=$((failures + 1))
+    return
+  fi
+
   if [[ "$mode" == "todo_fallback" ]]; then
     if [[ -z "$(frontmatter_scalar "$frontmatter" "topic_slug")" ]]; then
       log "missing required frontmatter field 'topic_slug' in $file"
@@ -423,8 +508,7 @@ check_feature_doc() {
 
   while IFS= read -r change_id; do
     [[ -z "$change_id" ]] && continue
-    if [[ ! -f "openspec/changes/$change_id/tasks.md" ]] && \
-      ! find openspec/changes/archive -type f \( -path "*/$change_id/tasks.md" -o -path "*/????-??-??-$change_id/tasks.md" \) | grep -q .; then
+    if ! change_has_tasks_artifact "$change_id"; then
       log "missing OpenSpec tasks artifact for change_id '$change_id' declared in $file"
       failures=$((failures + 1))
     fi
@@ -459,6 +543,80 @@ check_feature_doc() {
   done <<<"$todo_ids_raw"
 }
 
+check_todo_claim_to_openspec_task_mapping() {
+  local file line claim_id status_field change_field
+
+  while IFS= read -r file; do
+    while IFS= read -r line; do
+      claim_id="$(normalize_markdown_cell "$(markdown_table_column "$line" 1)")"
+      status_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 4)")"
+      change_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 7)")"
+
+      [[ -z "$claim_id" || -z "$status_field" ]] && continue
+      [[ "$status_field" != "active" && "$status_field" != "done" ]] && continue
+      [[ -z "$change_field" || "$change_field" == "pending" ]] && continue
+
+      if ! change_has_tasks_artifact "$change_field"; then
+        log "missing OpenSpec tasks mapping for TODO claim $claim_id in $file: $change_field"
+        failures=$((failures + 1))
+      fi
+    done < <(claim_ledger_rows "$file")
+  done < <(find docs/todos -maxdepth 1 -type f -name '*.md' ! -name 'README.md' | sort)
+}
+
+check_master_todo_slice_mapping_consistency() {
+  local project_file="docs/todos/project_overall_todos.md"
+  local detail_file="docs/todos/agentscope_domain_execution_todos.md"
+  local line status_field claim_id change_field detail_refs ref detail_change detail_claim_found
+  local detail_claim_map
+
+  if [[ ! -f "$project_file" || ! -f "$detail_file" ]]; then
+    return
+  fi
+
+  detail_claim_map="$(mktemp)"
+  trap 'rm -f "$detail_claim_map"' RETURN
+
+  while IFS= read -r line; do
+    claim_id="$(normalize_markdown_cell "$(markdown_table_column "$line" 1)")"
+    status_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 4)")"
+    change_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 7)")"
+
+    [[ -z "$claim_id" ]] && continue
+    [[ "$status_field" == "deprecated" ]] && continue
+    printf '%s|%s\n' "$claim_id" "$change_field" >>"$detail_claim_map"
+  done < <(claim_ledger_rows "$detail_file")
+
+  while IFS= read -r line; do
+    status_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 4)")"
+    [[ "$status_field" == "deprecated" ]] && continue
+
+    change_field="$(normalize_markdown_cell "$(markdown_table_column "$line" 7)")"
+    detail_refs="$(normalize_markdown_cell "$(markdown_table_column "$line" 8)")"
+
+    [[ -z "$detail_refs" || "$detail_refs" == "—" ]] && continue
+
+    while IFS= read -r ref; do
+      [[ -z "$ref" ]] && continue
+      detail_claim_found="$(awk -F'|' -v target="$ref" '$1 == target {print "1"; exit}' "$detail_claim_map")"
+      detail_change="$(awk -F'|' -v target="$ref" '$1 == target {print $2; exit}' "$detail_claim_map")"
+      if [[ -z "$detail_claim_found" ]]; then
+        log "missing Detail Claim Ref mapping in $project_file: $ref"
+        failures=$((failures + 1))
+        continue
+      fi
+
+      if [[ -n "$change_field" && "$change_field" != "pending" && -n "$detail_change" && "$detail_change" != "pending" && "$detail_change" != "$change_field" ]]; then
+        log "inconsistent OpenSpec change between $project_file and $detail_file for ref $ref"
+        failures=$((failures + 1))
+      fi
+    done < <(grep -oE 'CLM-[A-Za-z0-9-]+' <<<"$detail_refs")
+  done < <(claim_ledger_rows "$project_file")
+
+  rm -f "$detail_claim_map"
+  trap - RETURN
+}
+
 check_feature_indexes
 check_checkpoint_skill_mapping
 
@@ -466,6 +624,13 @@ while IFS= read -r file; do
   check_feature_doc "$file"
 done < <(find docs/features -maxdepth 1 -type f -name '*.md' ! -name 'README.md' | sort)
 
+while IFS= read -r file; do
+  check_feature_doc "$file"
+done < <(find docs/features/archive -maxdepth 1 -type f -name '*.md' ! -name 'README.md' | sort)
+
+check_todo_claim_to_openspec_task_mapping
+check_master_todo_slice_mapping_consistency
+
 if [[ $failures -gt 0 ]]; then
   log "failed with $failures issue(s)"
   exit 1
diff --git a/scripts/ci/check_test_failure_ownership.py b/scripts/ci/check_test_failure_ownership.py
new file mode 100644
index 00000000..cabd40e5
--- /dev/null
+++ b/scripts/ci/check_test_failure_ownership.py
@@ -0,0 +1,121 @@
+#!/usr/bin/env python3
+"""Validate failure-test ownership mapping used by the P0 gate."""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+if __package__ in {None, ""}:
+    # Allow direct execution: `python scripts/ci/check_test_failure_ownership.py`
+    sys.path.insert(0, str(Path(__file__).resolve().parents[2]))
+
+from scripts.ci.p0_gate import DEFAULT_CATEGORY_SPECS, CategorySpec
+
+
+def _normalize_selector_parts(selector: str) -> tuple[list[str], list[str]]:
+    segments = [segment.strip() for segment in selector.split("::") if segment.strip()]
+    if not segments:
+        return [], []
+
+    raw_path = segments[0].replace("\\", "/")
+    path_parts = [part for part in raw_path.split("/") if part and part != "."]
+    node_parts = [
+        # `pytest` parametrization suffixes (`test_x[param]`) are narrower matches
+        # than the base node (`test_x`) and should count as overlapping selectors.
+        segment.split("[", 1)[0]
+        for segment in segments[1:]
+    ]
+    return path_parts, node_parts
+
+
+def _selectors_overlap(left: str, right: str) -> bool:
+    left_path, left_nodes = _normalize_selector_parts(left)
+    right_path, right_nodes = _normalize_selector_parts(right)
+    if not left_path or not right_path:
+        return False
+
+    def _is_prefix(prefix: list[str], full: list[str]) -> bool:
+        if len(prefix) > len(full):
+            return False
+        return prefix == full[: len(prefix)]
+
+    if left_path == right_path:
+        return _is_prefix(left_nodes, right_nodes) or _is_prefix(right_nodes, left_nodes)
+
+    # `pytest` accepts file_or_dir selectors; a directory selector overlaps any
+    # descendant file/node selector under the same subtree.
+    if _is_prefix(left_path, right_path):
+        return not left_nodes
+    if _is_prefix(right_path, left_path):
+        return not right_nodes
+    return False
+
+
+def validate_category_specs(specs: list[CategorySpec]) -> list[str]:
+    """Return validation issues for failure ownership mapping specs."""
+    issues: list[str] = []
+    test_to_label: dict[str, str] = {}
+    selector_mappings: list[tuple[str, str]] = []
+
+    for spec in specs:
+        if not spec.tests:
+            issues.append(f"{spec.label}: missing test selectors")
+        if not spec.modules:
+            issues.append(f"{spec.label}: missing module ownership scope")
+
+        owner = spec.owner.strip()
+        if not owner:
+            issues.append(f"{spec.label}: missing owner")
+        elif not owner.startswith("@"):
+            issues.append(f"{spec.label}: owner must be a GitHub handle (starts with '@')")
+
+        for selector in spec.tests:
+            normalized = selector.strip()
+            if not normalized:
+                issues.append(f"{spec.label}: empty test selector")
+                continue
+
+            existing = test_to_label.get(normalized)
+            if existing and existing != spec.label:
+                issues.append(
+                    "duplicate test selector mapping: "
+                    f"{normalized} is mapped by both {existing} and {spec.label}"
+                )
+                continue
+
+            for mapped_selector, mapped_label in selector_mappings:
+                if mapped_label == spec.label:
+                    continue
+                if _selectors_overlap(normalized, mapped_selector):
+                    issues.append(
+                        "overlapping test selector mapping: "
+                        f"{normalized} ({spec.label}) overlaps with "
+                        f"{mapped_selector} ({mapped_label})"
+                    )
+                    break
+
+            test_to_label[normalized] = spec.label
+            selector_mappings.append((normalized, spec.label))
+
+    return issues
+
+
+def main() -> int:
+    specs = list(DEFAULT_CATEGORY_SPECS)
+    issues = validate_category_specs(specs)
+
+    if issues:
+        print("[failure-ownership] failed")
+        for issue in issues:
+            print(f"- {issue}")
+        return 1
+
+    print("[failure-ownership] passed")
+    for spec in specs:
+        print(f"- {spec.label}: owner={spec.owner}; tests={len(spec.tests)}; modules={len(spec.modules)}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())
diff --git a/scripts/ci/p0_gate.py b/scripts/ci/p0_gate.py
index cd28ee19..b61d5562 100644
--- a/scripts/ci/p0_gate.py
+++ b/scripts/ci/p0_gate.py
@@ -18,6 +18,7 @@ class CategorySpec:
     label: str
     tests: list[str]
     modules: list[str]
+    owner: str
     action: str
 
 
@@ -47,6 +48,7 @@ class CategoryResult:
             "examples/05-dare-coding-agent-enhanced/cli.py",
             "examples/06-dare-coding-agent-mcp/cli.py",
         ],
+        owner="@zts212653",
         action="inspect trust/policy/approval flow before tool invocation",
     ),
     CategorySpec(
@@ -61,6 +63,7 @@ class CategoryResult:
             "dare_framework/agent/_internal/execute_engine.py",
             "dare_framework/plan",
         ],
+        owner="@zts212653",
         action="inspect step execution order, fail-fast handling, and validated-plan routing",
     ),
     CategorySpec(
@@ -76,6 +79,7 @@ class CategoryResult:
             "dare_framework/observability/_internal/event_trace_bridge.py",
             "dare_framework/agent/builder.py",
         ],
+        owner="@zts212653",
         action="inspect SQLite event append/hash-chain/replay wiring and trace-aware event-log bridging",
     ),
 )
@@ -104,6 +108,7 @@ def format_summary(results: list[CategoryResult]) -> str:
                 f"- {result.spec.label}",
                 f"  tests: {failed_tests}",
                 f"  modules: {modules}",
+                f"  owner: {result.spec.owner}",
                 f"  action: {result.spec.action}",
             ]
         )
diff --git a/tests/unit/test_check_test_failure_ownership.py b/tests/unit/test_check_test_failure_ownership.py
new file mode 100644
index 00000000..84a42d0d
--- /dev/null
+++ b/tests/unit/test_check_test_failure_ownership.py
@@ -0,0 +1,74 @@
+from __future__ import annotations
+
+from scripts.ci.check_test_failure_ownership import validate_category_specs
+from scripts.ci.p0_gate import CategorySpec
+
+
+def _spec(
+    label: str,
+    *,
+    tests: list[str] | None = None,
+    modules: list[str] | None = None,
+    owner: str = "@zts212653",
+) -> CategorySpec:
+    return CategorySpec(
+        label=label,
+        tests=tests or ["tests/example.py::test_case"],
+        modules=modules or ["dare_framework/example.py"],
+        owner=owner,
+        action="inspect category",
+    )
+
+
+def test_validate_category_specs_accepts_valid_mapping() -> None:
+    issues = validate_category_specs(
+        [
+            _spec("SECURITY_REGRESSION", tests=["tests/a.py::test_x"]),
+            _spec("STEP_EXEC_REGRESSION", tests=["tests/b.py::test_y"]),
+        ]
+    )
+
+    assert issues == []
+
+
+def test_validate_category_specs_rejects_duplicate_test_mapping() -> None:
+    issues = validate_category_specs(
+        [
+            _spec("SECURITY_REGRESSION", tests=["tests/a.py::test_x"]),
+            _spec("STEP_EXEC_REGRESSION", tests=["tests/a.py::test_x"]),
+        ]
+    )
+
+    assert any("duplicate test selector mapping" in issue for issue in issues)
+
+
+def test_validate_category_specs_rejects_overlapping_test_mapping() -> None:
+    issues = validate_category_specs(
+        [
+            _spec("SECURITY_REGRESSION", tests=["tests/a.py"]),
+            _spec("STEP_EXEC_REGRESSION", tests=["tests/a.py::test_x"]),
+        ]
+    )
+
+    assert any("overlapping test selector mapping" in issue for issue in issues)
+
+
+def test_validate_category_specs_rejects_overlapping_directory_selector_mapping() -> None:
+    issues = validate_category_specs(
+        [
+            _spec("SECURITY_REGRESSION", tests=["tests/unit"]),
+            _spec("STEP_EXEC_REGRESSION", tests=["tests/unit/test_a.py::test_x"]),
+        ]
+    )
+
+    assert any("overlapping test selector mapping" in issue for issue in issues)
+
+
+def test_validate_category_specs_rejects_missing_owner() -> None:
+    issues = validate_category_specs(
+        [
+            _spec("SECURITY_REGRESSION", owner=""),
+        ]
+    )
+
+    assert any("missing owner" in issue for issue in issues)
diff --git a/tests/unit/test_checkpoint_defaults.py b/tests/unit/test_checkpoint_defaults.py
new file mode 100644
index 00000000..017d9edf
--- /dev/null
+++ b/tests/unit/test_checkpoint_defaults.py
@@ -0,0 +1,52 @@
+from __future__ import annotations
+
+import importlib
+from dataclasses import dataclass
+
+
+def test_checkpoint_defaults_module_exports_are_importable() -> None:
+    defaults = importlib.import_module("dare_framework.checkpoint.defaults")
+
+    for symbol in (
+        "MemoryCheckpointStore",
+        "DefaultCheckpointSaveRestore",
+        "StmContributor",
+        "WorkspaceGitContributor",
+        "SessionStateContributor",
+        "SessionContextContributor",
+    ):
+        assert hasattr(defaults, symbol), f"missing checkpoint default symbol: {symbol}"
+
+
+@dataclass
+class _DummyConfig:
+    model: str
+
+
+@dataclass
+class _DummySessionContext:
+    session_id: str
+    task_id: str
+    config: _DummyConfig | None
+
+
+@dataclass
+class _DummyCtx:
+    session_context: _DummySessionContext | None
+
+
+def test_session_context_contributor_preserves_serialized_config_dict() -> None:
+    defaults = importlib.import_module("dare_framework.checkpoint.defaults")
+    contributor = defaults.SessionContextContributor()
+    ctx = _DummyCtx(
+        session_context=_DummySessionContext(
+            session_id="s-1",
+            task_id="t-1",
+            config=_DummyConfig(model="gpt-4.1"),
+        )
+    )
+
+    payload = contributor.serialize(ctx)
+
+    assert payload is not None
+    assert payload["config"] == {"model": "gpt-4.1"}
diff --git a/tests/unit/test_governance_intent_gate.py b/tests/unit/test_governance_intent_gate.py
index 50ac15b7..ea051540 100644
--- a/tests/unit/test_governance_intent_gate.py
+++ b/tests/unit/test_governance_intent_gate.py
@@ -103,6 +103,7 @@ def test_implementation_changes_require_governed_feature_doc_update(self) -> Non
 
         self.assertNotEqual(result.returncode, 0)
         self.assertIn("must update at least one governed feature doc", result.stdout)
+        self.assertNotIn("unbound variable", result.stderr)
 
     def test_implementation_changes_fail_when_intent_pr_not_merged(self) -> None:
         result = self._run_gate(
diff --git a/tests/unit/test_governance_traceability_gate.py b/tests/unit/test_governance_traceability_gate.py
index 410abff9..fe818e40 100644
--- a/tests/unit/test_governance_traceability_gate.py
+++ b/tests/unit/test_governance_traceability_gate.py
@@ -86,7 +86,21 @@ def _base_tree(root: Path) -> None:
 - Move docs here only after closeout.
 """,
     )
-    _write(root / "docs" / "features" / "archive" / "archived-change.md", "# archived\n")
+    _write(
+        root / "docs" / "features" / "archive" / "archived-change.md",
+        """---
+change_ids: ["archived-change"]
+doc_kind: feature
+topics: ["governance", "archive"]
+created: 2026-03-01
+updated: 2026-03-01
+status: archived
+mode: openspec
+---
+
+# Feature: archived-change
+""",
+    )
     _write(
         root / "docs" / "features" / "templates" / "feature_aggregation_template.md",
         """# Feature Aggregation Template
@@ -113,11 +127,34 @@ def _base_tree(root: Path) -> None:
 | Claim ID | TODO Scope | Owner | Status | Declared At | Expires At | OpenSpec Change | Notes |
 |---|---|---|---|---|---|---|---|
 | CLM-DEMO | D2-1~D2-2 | demo | active | 2026-03-03 | 2026-03-10 | `demo-change` | demo |
+""",
+    )
+    _write(
+        root / "docs" / "todos" / "project_overall_todos.md",
+        """# Demo Project Overall TODO
+
+## 1.1 认领声明（Claim Ledger）
+
+| Claim ID | TODO Scope | Owner | Status | Declared At | Expires At | OpenSpec Change | Detail Claim Ref | Notes |
+|---|---|---|---|---|---|---|---|---|
+| CLM-AG1 | T5-2 | demo | done | 2026-03-03 | 2026-03-10 | `demo-change` | `CLM-D9` | demo |
+""",
+    )
+    _write(
+        root / "docs" / "todos" / "agentscope_domain_execution_todos.md",
+        """# Demo AgentScope Board
+
+## 0.1 认领声明（Claim Ledger）
+
+| Claim ID | TODO Scope | Owner | Status | Declared At | Expires At | OpenSpec Change | Project Claim Ref | Notes |
+|---|---|---|---|---|---|---|---|---|
+| CLM-D9 | D9-1~D9-2 | demo | done | 2026-03-03 | 2026-03-10 | `demo-change` | `CLM-AG1` | demo |
 """,
     )
     _write(root / "openspec" / "changes" / "demo-change" / "proposal.md", "# proposal\n")
     _write(root / "openspec" / "changes" / "demo-change" / "design.md", "# design\n")
     _write(root / "openspec" / "changes" / "demo-change" / "tasks.md", "- [ ] demo\n")
+    _write(root / "openspec" / "changes" / "archive" / "2026-03-01-archived-change" / "tasks.md", "- [x] archived\n")
     _write(
         root / "docs" / "governance" / "Documentation_Management_Model.md",
         """# Documentation Management Model
@@ -166,6 +203,19 @@ def test_gate_fails_when_feature_template_is_missing(self) -> None:
         self.assertNotEqual(result.returncode, 0)
         self.assertIn("missing feature aggregation template", result.stdout)
 
+    def test_gate_fails_when_archived_feature_doc_frontmatter_is_missing_required_field(self) -> None:
+        def mutate(root: Path) -> None:
+            archived = root / "docs" / "features" / "archive" / "archived-change.md"
+            archived.write_text(
+                archived.read_text(encoding="utf-8").replace("status: archived\n", ""),
+                encoding="utf-8",
+            )
+
+        result = self._run_gate(mutate)
+
+        self.assertNotEqual(result.returncode, 0)
+        self.assertIn("missing required frontmatter field 'status'", result.stdout)
+
     def test_gate_fails_when_active_feature_doc_is_not_indexed(self) -> None:
         def mutate(root: Path) -> None:
             readme = root / "docs" / "features" / "README.md"
@@ -405,6 +455,48 @@ def mutate(root: Path) -> None:
         self.assertNotEqual(result.returncode, 0)
         self.assertIn("missing TODO mapping for feature doc", result.stdout)
 
+    def test_gate_fails_when_done_or_active_claim_has_no_tasks_artifact(self) -> None:
+        def mutate(root: Path) -> None:
+            project_doc = root / "docs" / "todos" / "project_overall_todos.md"
+            project_doc.write_text(
+                project_doc.read_text(encoding="utf-8").replace("`demo-change`", "`missing-change`"),
+                encoding="utf-8",
+            )
+
+        result = self._run_gate(mutate)
+
+        self.assertNotEqual(result.returncode, 0)
+        self.assertIn("missing OpenSpec tasks mapping for TODO claim", result.stdout)
+
+    def test_gate_fails_when_project_claim_detail_ref_is_missing(self) -> None:
+        def mutate(root: Path) -> None:
+            project_doc = root / "docs" / "todos" / "project_overall_todos.md"
+            project_doc.write_text(
+                project_doc.read_text(encoding="utf-8").replace("`CLM-D9`", "`CLM-D404`"),
+                encoding="utf-8",
+            )
+
+        result = self._run_gate(mutate)
+
+        self.assertNotEqual(result.returncode, 0)
+        self.assertIn("missing Detail Claim Ref mapping in docs/todos/project_overall_todos.md", result.stdout)
+
+    def test_gate_accepts_detail_claim_ref_with_empty_change_cell(self) -> None:
+        def mutate(root: Path) -> None:
+            detail_doc = root / "docs" / "todos" / "agentscope_domain_execution_todos.md"
+            detail_doc.write_text(
+                detail_doc.read_text(encoding="utf-8").replace(
+                    "`demo-change` | `CLM-AG1`",
+                    " | `CLM-AG1`",
+                ),
+                encoding="utf-8",
+            )
+
+        result = self._run_gate(mutate)
+
+        self.assertEqual(result.returncode, 0)
+        self.assertIn("passed", result.stdout)
+
     def test_gate_accepts_date_prefixed_archived_change_tasks(self) -> None:
         def mutate(root: Path) -> None:
             feature_doc = root / "docs" / "features" / "demo-change.md"
@@ -417,6 +509,16 @@ def mutate(root: Path) -> None:
                 todo_doc.read_text(encoding="utf-8").replace("`demo-change`", "`archived-change`"),
                 encoding="utf-8",
             )
+            project_doc = root / "docs" / "todos" / "project_overall_todos.md"
+            project_doc.write_text(
+                project_doc.read_text(encoding="utf-8").replace("`demo-change`", "`archived-change`"),
+                encoding="utf-8",
+            )
+            detail_doc = root / "docs" / "todos" / "agentscope_domain_execution_todos.md"
+            detail_doc.write_text(
+                detail_doc.read_text(encoding="utf-8").replace("`demo-change`", "`archived-change`"),
+                encoding="utf-8",
+            )
             active_change_dir = root / "openspec" / "changes" / "demo-change"
             for path in active_change_dir.iterdir():
                 path.unlink()
diff --git a/tests/unit/test_p0_gate_ci.py b/tests/unit/test_p0_gate_ci.py
index 61b1ec2d..e7e391e7 100644
--- a/tests/unit/test_p0_gate_ci.py
+++ b/tests/unit/test_p0_gate_ci.py
@@ -7,12 +7,14 @@ def _spec(
     label: str,
     *,
     modules: list[str] | None = None,
+    owner: str = "@zts212653",
     action: str = "inspect category",
 ) -> CategorySpec:
     return CategorySpec(
         label=label,
         tests=["tests/example.py::test_case"],
         modules=modules or ["module.one", "module.two"],
+        owner=owner,
         action=action,
     )
 
@@ -89,6 +91,7 @@ def test_format_summary_reports_failures_with_modules_and_action() -> None:
             "- STEP_EXEC_REGRESSION",
             "  tests: tests/integration/test_p0_conformance_gate.py::test_step_driven_session_stops_after_first_failed_step",
             "  modules: dare_framework/agent/dare_agent.py, dare_framework/agent/_internal/execute_engine.py",
+            "  owner: @zts212653",
             "  action: inspect step execution order and fail-fast handling",
         ]
     )
diff --git a/tests/unit/test_package_initializers_facade_pattern.py b/tests/unit/test_package_initializers_facade_pattern.py
index 3990969b..1bc66235 100644
--- a/tests/unit/test_package_initializers_facade_pattern.py
+++ b/tests/unit/test_package_initializers_facade_pattern.py
@@ -4,6 +4,42 @@
 from pathlib import Path
 
 
+def _is_internal_module_path(module: str) -> bool:
+    return module == "_internal" or module.startswith("_internal.") or "._internal" in module
+
+
+def _find_direct_internal_import(node: ast.stmt) -> str | None:
+    if isinstance(node, ast.ImportFrom):
+        module = node.module or ""
+        if module and _is_internal_module_path(module):
+            return f"{'.' * node.level}{module}"
+
+        # `from . import _internal` uses `module is None` and stores names in aliases.
+        for alias in node.names:
+            if _is_internal_module_path(alias.name):
+                return f"{'.' * node.level}{alias.name}"
+        return None
+
+    if isinstance(node, ast.Import):
+        for alias in node.names:
+            if _is_internal_module_path(alias.name):
+                return alias.name
+    return None
+
+
+def test_internal_import_detection_covers_relative_syntax() -> None:
+    cases = {
+        "from ._internal.foo import Bar": "._internal.foo",
+        "from .._internal import Foo": ".._internal",
+        "from . import _internal": "._internal",
+        "from dare_framework.tool._internal.tools import EchoTool": "dare_framework.tool._internal.tools",
+        "from dare_framework.tool.defaults import EchoTool": None,
+    }
+    for source, expected in cases.items():
+        node = ast.parse(source).body[0]
+        assert _find_direct_internal_import(node) == expected
+
+
 def test_package_initializers_follow_facade_pattern() -> None:
     """Asserts that all dare_framework initializers use the facade pattern.
     
@@ -12,6 +48,8 @@ def test_package_initializers_follow_facade_pattern() -> None:
     2. No class or function definitions.
     3. Assignments allowed only for metadata (e.g., __all__, __version__).
     4. Imports allowed for re-exporting.
+    5. Star imports are prohibited.
+    6. Public facades must not import from `._internal` directly.
     """
     repo_root = Path(__file__).resolve().parents[2]
     package_root = repo_root / "dare_framework"
@@ -21,6 +59,7 @@ def test_package_initializers_follow_facade_pattern() -> None:
     violations: list[str] = []
     for path in init_files:
         source = path.read_text(encoding="utf-8")
+        is_public_facade = "_internal" not in path.parts
         if not source.strip():
              # Empty files are okay if they are just placeholders, 
              # but the user wanted docstrings.
@@ -68,6 +107,19 @@ def test_package_initializers_follow_facade_pattern() -> None:
                     violations.append(f"{path.relative_to(repo_root)}: Prohibited assignment (only __all__/__version__ etc allowed)")
 
             # Rule 4: Imports are allowed (for re-exporting)
+            if isinstance(node, ast.ImportFrom) and any(alias.name == "*" for alias in node.names):
+                violations.append(f"{path.relative_to(repo_root)}: Prohibited star import in package initializer")
+                continue
+
+            # Rule 6: Public facades must not directly import internal modules.
+            if is_public_facade:
+                direct_internal_import = _find_direct_internal_import(node)
+                if direct_internal_import is not None:
+                    violations.append(
+                        f"{path.relative_to(repo_root)}: Prohibited direct _internal import ({direct_internal_import})"
+                    )
+                    continue
+
             if isinstance(node, (ast.Import, ast.ImportFrom)):
                 continue
             
diff --git a/tests/unit/test_security_boundary.py b/tests/unit/test_security_boundary.py
index 029c7a19..ef6776c0 100644
--- a/tests/unit/test_security_boundary.py
+++ b/tests/unit/test_security_boundary.py
@@ -2,6 +2,7 @@
 
 import pytest
 
+from dare_framework.security import DefaultSecurityBoundary
 from dare_framework.security.errors import SECURITY_TRUST_DERIVATION_FAILED, SecurityBoundaryError
 from dare_framework.security.impl import NoOpSecurityBoundary, PolicySecurityBoundary
 from dare_framework.security.types import PolicyDecision, RiskLevel
@@ -44,6 +45,26 @@ async def test_policy_security_boundary_requires_approval_for_high_risk() -> Non
     assert decision is PolicyDecision.APPROVE_REQUIRED
 
 
+@pytest.mark.asyncio
+async def test_default_security_boundary_remains_permissive_for_high_risk() -> None:
+    boundary = DefaultSecurityBoundary()
+    trusted = await boundary.verify_trust(
+        input={"command": "rm -rf /tmp/foo"},
+        context={
+            "capability_id": "run_command",
+            "risk_level": RiskLevel.NON_IDEMPOTENT_EFFECT.value,
+            "requires_approval": True,
+        },
+    )
+    decision = await boundary.check_policy(
+        action="invoke_tool",
+        resource="run_command",
+        context={"trusted_input": trusted, "capability_id": "run_command", "requires_approval": True},
+    )
+
+    assert decision is PolicyDecision.ALLOW
+
+
 @pytest.mark.asyncio
 async def test_policy_security_boundary_denies_blocked_capability() -> None:
     boundary = PolicySecurityBoundary(deny_capability_ids={"run_command"})