docs/gitea-execution-profiles.md

@@ -589,6 +589,47 @@ When dynamic profile switching is enabled and a profile is activated via `gitea_
 2. Call `gitea_whoami` with the target remote to prove and verify the fresh Gitea authenticated identity.
 This guarantees the active profile operations align with the actual Gitea authenticated user credential.
 
+### 4. Review-State Invalidation on Profile Switch (#690)
+
+A cross-profile activation (e.g. reviewer → author → reviewer) is a session
+boundary for formal review state. On any switch where the activated profile
+differs from the previous one, `gitea_activate_profile` invalidates, in
+memory **and** in durable session state (for both the old and new profile
+identities):
+
+- preflight identity/capability stamps (`gitea_whoami` / `gitea_resolve_task_capability` proof),
+- review workflow-load proof (`gitea_load_review_workflow`),
+- the review decision lock (including `final_review_decision_ready` markers),
+- the reviewer PR session lease binding,
+- live namespace-health assessments.
+
+Before any formal verdict (`gitea_mark_final_review_decision` /
+`gitea_submit_pr_review`) the full reviewer preflight must be re-established
+under the new profile: `gitea_whoami`, `gitea_load_review_workflow`,
+`gitea_resolve_task_capability(review_pr)`, live head re-pin, and lease
+re-acquire/adopt. Switching back to the earlier profile does **not**
+resurrect the prior run — durable state keyed by either profile identity is
+cleared at switch time.
+
+The supported pattern remains **separate session/namespace per role**
+(dual-namespace, §2): file author-side follow-ups from an author session,
+not by hopping profiles inside a formal review run. Runtime profile
+switching is the operator-approved exception and always carries the
+re-preflight cost above.
+
+### 5. Namespace Provenance (#690)
+
+The server cannot derive its own client-managed MCP namespace name, so a
+launcher may declare it via the `GITEA_MCP_NAMESPACE` environment variable
+(e.g. `gitea-reviewer`). `gitea_whoami`, `gitea_get_runtime_context`, and
+`gitea_resolve_task_capability` report `namespace_provenance` — the
+configured client namespace, the active execution profile, and, for tasks
+with a required namespace (`review_pr` → `gitea-reviewer`, `merge_pr` →
+`gitea-merger`), a mismatch verdict. A declared namespace that disagrees
+with the requested task's required namespace **fails closed**. An
+undeclared namespace is reported as `unknown` and is never treated as
+proof either way.
+
 ## Gitea MCP Runtime Isolation and Worktree Safety
 
 To ensure high availability and prevent broken feature worktrees from disabling essential security/identity controls, the Gitea MCP server implements runtime isolation:

docs/mcp-namespace-health.md

@@ -86,3 +86,24 @@ When a namespace returns EOF, follow
 
 When blocked, repair the IDE namespace and re-record a healthy
 `client_namespace` assessment before retrying the mutation.
+
+## Namespace provenance (#690)
+
+A server process cannot derive the name of the client-managed namespace it is
+registered under, so the launcher may declare it with the
+`GITEA_MCP_NAMESPACE` environment variable (e.g. `GITEA_MCP_NAMESPACE=gitea-reviewer`).
+
+- `gitea_whoami`, `gitea_get_runtime_context`, and
+  `gitea_resolve_task_capability` report `namespace_provenance`: the declared
+  client namespace, the active execution profile, and — for tasks with a
+  required namespace (`review_pr`/`submit_review` → `gitea-reviewer`,
+  `merge_pr` → `gitea-merger`) — a `mismatch` verdict.
+- A declared namespace that disagrees with the requested task's required
+  namespace **fails closed** (`allowed_in_current_session=false` with a STOP
+  guidance entry).
+- An undeclared namespace is reported as `namespace_source="unknown"` and is
+  never treated as proof either way.
+- A profile switch via `gitea_activate_profile` clears all recorded live
+  namespace-health assessments; re-probe through the client before further
+  review/merge mutations.
+

gitea_mcp_server.py

@@ -839,6 +839,75 @@ def _invalidate_preflight_identity_state() -> None:
     _clear_preflight_capability_state()
 
 
+# #690: session-boundary invalidation record for the most recent cross-profile
+# activation. Surfaced in runtime diagnostics so a formal review run can prove
+# its state was reset by a profile switch and must be fully re-established.
+_PROFILE_SWITCH_INVALIDATION: dict | None = None
+
+
+def _invalidate_review_state_on_profile_switch(
+    before_profile: str,
+    after_profile: str,
+) -> dict:
+    """Invalidate review-critical session state on a profile switch (#690).
+
+    Workflow-load proof, reviewer lease binding, the review decision lock,
+    live namespace health, and preflight identity/capability stamps recorded
+    under the prior profile are contaminated for the new role. Durable state
+    keyed by *either* profile identity is cleared so a reviewer → author →
+    reviewer hop cannot resurrect a stale review run: the full reviewer
+    preflight (gitea_whoami, gitea_load_review_workflow,
+    gitea_resolve_task_capability(review_pr), live head re-pin, lease
+    re-acquire/adopt) must be re-established before any formal verdict.
+    """
+    global _PROFILE_SWITCH_INVALIDATION
+    invalidated: list[str] = []
+
+    _invalidate_preflight_identity_state()
+    invalidated.append("preflight_identity_capability")
+
+    review_workflow_load.clear_review_workflow_load()
+    invalidated.append("review_workflow_load")
+
+    _save_review_decision_lock(None)
+    invalidated.append("review_decision_lock")
+
+    reviewer_pr_lease.clear_session_lease()
+    invalidated.append("reviewer_session_lease")
+
+    if _LIVE_NAMESPACE_HEALTH:
+        _LIVE_NAMESPACE_HEALTH.clear()
+        invalidated.append("live_namespace_health")
+
+    # Durable records keyed by either profile identity must not survive the
+    # switch, or activating author → reviewer → author could revive a stale
+    # review run without re-preflight.
+    for identity in {before_profile, after_profile}:
+        if not identity:
+            continue
+        try:
+            mcp_session_state.clear_state(
+                kind=mcp_session_state.KIND_DECISION_LOCK,
+                profile_identity=identity,
+            )
+            mcp_session_state.clear_state(
+                kind=mcp_session_state.KIND_WORKFLOW_LOAD,
+                profile_identity=identity,
+            )
+        except Exception:
+            pass  # best-effort durable cleanup; in-memory state already reset
+    invalidated.append("durable_profile_state")
+
+    _PROFILE_SWITCH_INVALIDATION = {
+        "from_profile": before_profile,
+        "to_profile": after_profile,
+        "invalidated": invalidated,
+        "invalidated_at": datetime.now(timezone.utc).isoformat(),
+        "re_preflight_required": True,
+    }
+    return dict(_PROFILE_SWITCH_INVALIDATION)
+
+
 def record_preflight_check(
     type_name: str,
     resolved_role: str | None = None,
@@ -17210,6 +17279,11 @@ def gitea_whoami(
         "session_context_audit": session_ctx.mutation_context_audit_fields(),
         "identity_match": not id_match.get("block"),
         "identity_match_reasons": id_match.get("reasons") or [],
+        # #690 AC4: report launcher-declared client namespace alongside the
+        # active execution profile so drift is visible in diagnostics.
+        "namespace_provenance": mcp_namespace_health.namespace_provenance(
+            active_profile=profile["profile_name"]
+        ),
     }
     if id_match.get("block"):
         _invalidate_preflight_identity_state()
@@ -18108,6 +18182,11 @@ def gitea_get_runtime_context(
         "shell_health": native_mcp_preference.shell_health_status(),
         "workflow_load_proof": review_workflow_load.workflow_load_status(
             PROJECT_ROOT),
+        # #690: namespace provenance + profile-switch invalidation evidence.
+        "namespace_provenance": mcp_namespace_health.namespace_provenance(
+            active_profile=profile["profile_name"]
+        ),
+        "profile_switch_invalidation": _PROFILE_SWITCH_INVALIDATION,
     }
 
     # #702: read-only visibility into the inherited GITEA_ACTIVE_WORKTREE
@@ -18611,6 +18690,17 @@ def gitea_activate_profile(
         source="gitea_activate_profile",
     )
 
+    # 4.7 #690: a profile switch is a session-boundary event for review state.
+    # Any workflow-load proof, reviewer lease, decision lock, namespace
+    # health, or preflight stamp recorded under the prior profile is
+    # contaminated for the new role and must be re-established under the new
+    # profile before any formal review verdict.
+    switch_invalidation = None
+    if before_profile != after_profile:
+        switch_invalidation = _invalidate_review_state_on_profile_switch(
+            before_profile, after_profile
+        )
+
     # 5. Audit the switch if auditing is on
     _audit(
         "activate_profile",
@@ -18621,11 +18711,12 @@ def gitea_activate_profile(
             "before": before_profile,
             "after": after_profile,
             "session_context": session_ctx.mutation_context_audit_fields(),
+            "review_state_invalidated": bool(switch_invalidation),
         },
         username=after_identity,
     )
 
-    return {
+    result = {
         "success": True,
         "message": f"Successfully activated profile '{profile_name}' (fresh identity verification complete).",
         "before_profile": before_profile,
@@ -18635,6 +18726,18 @@ def gitea_activate_profile(
         "session_context_audit": session_ctx.mutation_context_audit_fields(),
         "auto_profile_substitution": False,
     }
+    if switch_invalidation is not None:
+        result["review_state_invalidation"] = switch_invalidation
+        result["re_preflight_required"] = True
+        result["exact_next_action"] = (
+            "Profile switch invalidated workflow-load proof, reviewer lease, "
+            "decision lock, and preflight stamps (#690). Before any formal "
+            "review verdict, re-run the full reviewer preflight: "
+            "gitea_whoami, gitea_load_review_workflow, "
+            "gitea_resolve_task_capability(review_pr), live head re-pin, and "
+            "lease re-acquire/adopt."
+        )
+    return result
 
 
 @mcp.tool()
@@ -20879,12 +20982,22 @@ def gitea_resolve_task_capability(
             f"{required_role} task '{task}' even if nearby permissions are "
             "present (fail closed)."
         )
+    # #690 AC4: when the launcher declares a client namespace, a task with a
+    # required namespace must fail closed on mismatch (e.g. review_pr served
+    # from an author namespace).
+    ns_provenance = mcp_namespace_health.namespace_provenance(
+        task=task_key, active_profile=profile.get("profile_name")
+    )
+    ns_mismatch_reason = None
+    if ns_provenance.get("mismatch"):
+        ns_mismatch_reason = "; ".join(ns_provenance.get("reasons") or [])
     cross_host_block = bool(remote_assess.get("block"))
     identity_block = bool(id_assess.get("block"))
     drift_block = bool(ctx_assess.get("block"))
     allowed_in_current_session = (
         permission_allowed_in_current_session
         and role_matches_current_session
+        and not ns_provenance.get("mismatch")
         and not cross_host_block
         and not identity_block
         and not drift_block
@@ -20935,6 +21048,8 @@ def gitea_resolve_task_capability(
             )
         if role_mismatch_reason:
             deny_parts.append(role_mismatch_reason)
+        if ns_mismatch_reason:
+            deny_parts.append(ns_mismatch_reason)
         if deny_parts:
             reason_msg = "; ".join(deny_parts)
         elif configured and switching:
@@ -21012,6 +21127,8 @@ def gitea_resolve_task_capability(
     task_role_guidance = []
     if role_mismatch_reason:
         task_role_guidance.append(f"STOP: {role_mismatch_reason}")
+    if ns_mismatch_reason:
+        task_role_guidance.append(f"STOP: {ns_mismatch_reason}")
     if required_role == "reviewer":
         if allowed_in_current_session:
             task_role_guidance.append(
@@ -21078,6 +21195,7 @@ def gitea_resolve_task_capability(
         "session_context_audit": session_ctx.mutation_context_audit_fields(),
         "profile_remote_compatible": not cross_host_block,
         "identity_match": not identity_block,
+        "namespace_provenance": ns_provenance,
         "auto_profile_substitution": False,
     }
     # #685: report typed reconnect blocker without mutating config or exiting.

mcp_namespace_health.py

@@ -16,6 +16,7 @@ Probe sources
 
 from __future__ import annotations
 
+import os
 from typing import Any
 
 
@@ -57,8 +58,56 @@ SAFE_ENV_KEYS = (
     "GITEA_SERVICE",
     "GITEA_EXECUTION_ROLE",
     "GITEA_MCP_CONFIG",
+    "GITEA_MCP_NAMESPACE",
 )
 
+# Optional launcher-provided env declaring the client-managed MCP namespace
+# this process is registered under (e.g. ``gitea-reviewer``). The server
+# cannot derive its own IDE namespace name, so the launcher declares it; when
+# declared, reviewers/mergers can fail closed on a namespace/task mismatch
+# (#690 AC4). Absence means "unknown" — reported, never guessed.
+NAMESPACE_ENV = "GITEA_MCP_NAMESPACE"
+
+
+def configured_client_namespace(env: dict[str, str] | None = None) -> str | None:
+    """Return the launcher-declared client namespace, or None when unknown."""
+    source = os.environ if env is None else env
+    value = (source.get(NAMESPACE_ENV) or "").strip()
+    return value or None
+
+
+def namespace_provenance(
+    task: str | None = None,
+    *,
+    active_profile: str | None = None,
+    env: dict[str, str] | None = None,
+) -> dict[str, Any]:
+    """Report configured client namespace vs active execution profile (#690).
+
+    When *task* carries a required namespace (``TASK_REQUIRED_NAMESPACES``)
+    and the launcher declared a different one, ``mismatch`` is True and the
+    caller must fail closed for that task. An undeclared namespace is
+    reported as unknown — never treated as proof either way.
+    """
+    configured = configured_client_namespace(env)
+    required = TASK_REQUIRED_NAMESPACES.get(task or "")
+    mismatch = bool(configured and required and configured != required)
+    reasons: list[str] = []
+    if mismatch:
+        reasons.append(
+            f"configured client namespace '{configured}' does not match "
+            f"required namespace '{required}' for task '{task}' (fail closed)"
+        )
+    return {
+        "configured_namespace": configured,
+        "namespace_source": NAMESPACE_ENV if configured else "unknown",
+        "active_profile": active_profile,
+        "requested_task": task,
+        "required_namespace": required,
+        "mismatch": mismatch,
+        "reasons": reasons,
+    }
+
 
 def _as_list(value: Any) -> list[str] | None:
     if value is None:

tests/conftest.py

@@ -41,6 +41,7 @@ def _reset_mutation_authority(monkeypatch):
         "GITEA_REVIEWER_WORKTREE",
         "GITEA_MERGER_WORKTREE",
         "GITEA_RECONCILER_WORKTREE",
+        "GITEA_MCP_NAMESPACE",
     ]:
         monkeypatch.delenv(env_key, raising=False)
 
@@ -115,6 +116,7 @@ def _reset_mutation_authority(monkeypatch):
         monkeypatch.setattr(mcp_server, "_ACTOR_IDENTITY_CACHE", {})
     monkeypatch.setattr(mcp_server, "_REVIEW_DECISION_LOCK", None)
     monkeypatch.setattr(mcp_server, "_LIVE_NAMESPACE_HEALTH", {})
+    monkeypatch.setattr(mcp_server, "_PROFILE_SWITCH_INVALIDATION", None)
     monkeypatch.setattr(mcp_server, "_preflight_whoami_called", False)
     monkeypatch.setattr(mcp_server, "_preflight_capability_called", False)
     monkeypatch.setattr(mcp_server, "_preflight_resolved_role", None)

tests/test_issue_690_profile_switch_review_guard.py

@@ -0,0 +1,274 @@
+"""Regression coverage for #690: cross-role profile activation invalidation.
+
+A mid-run profile switch (e.g. reviewer → author → reviewer) must invalidate
+workflow-load proof, reviewer lease binding, review decision lock, live
+namespace health, and preflight identity/capability stamps, and must require
+a full reviewer preflight before any formal verdict. Namespace provenance
+must be reported and fail closed on task/namespace mismatch.
+"""
+import json
+import os
+import sys
+import tempfile
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import gitea_config
+import mcp_namespace_health
+import mcp_server
+import mcp_session_state
+import review_workflow_load
+import reviewer_pr_lease
+
+from tests.test_runtime_clarity import CONFIG_SWITCHING_ENABLED
+
+
+class TestProfileSwitchReviewGuard(unittest.TestCase):
+    def setUp(self):
+        self._remotes_patch = patch.dict(mcp_server.REMOTES, {
+            "dadeschools": {"host": "gitea.example.com", "org": "Example-Org", "repo": "Example-Repo"},
+            "prgs": {"host": "gitea.example.com", "org": "Example-Org", "repo": "Example-Repo"},
+        })
+        self._remotes_patch.start()
+        mcp_server._IDENTITY_CACHE.clear()
+        gitea_config._active_profile_override = None
+        self._dir = tempfile.TemporaryDirectory()
+        self.config_path = os.path.join(self._dir.name, "profiles.json")
+        with open(self.config_path, "w", encoding="utf-8") as fh:
+            fh.write(json.dumps(CONFIG_SWITCHING_ENABLED))
+
+    def tearDown(self):
+        self._remotes_patch.stop()
+        mcp_server._IDENTITY_CACHE.clear()
+        gitea_config._active_profile_override = None
+        self._dir.cleanup()
+
+    def _env(self, profile="reviewer-profile"):
+        return {
+            "GITEA_MCP_CONFIG": self.config_path,
+            "GITEA_MCP_PROFILE": profile,
+            "GITEA_TOKEN_AUTHOR": "author-pass",
+            "GITEA_TOKEN_REVIEWER": "reviewer-pass",
+            "GITEA_TOKEN_MERGER": "merger-pass",
+        }
+
+    def _seed_contaminated_review_state(self):
+        """Simulate an in-flight reviewer run under reviewer-profile."""
+        mcp_server._preflight_whoami_called = True
+        mcp_server._preflight_capability_called = True
+        mcp_server._preflight_resolved_role = "reviewer"
+        mcp_server._preflight_resolved_task = "review_pr"
+        review_workflow_load._REVIEW_WORKFLOW_LOAD = {"loaded": True}
+        mcp_server._REVIEW_DECISION_LOCK = {
+            "session_profile": "reviewer-profile",
+            "final_review_decision_ready": True,
+            "ready_pr_number": 688,
+        }
+        reviewer_pr_lease.record_session_lease(
+            {"session_id": "lease-session-1", "pr_number": 688}
+        )
+        mcp_server._LIVE_NAMESPACE_HEALTH["gitea-reviewer"] = {
+            "namespace": "gitea-reviewer",
+            "healthy": True,
+            "ide_namespace_proven": True,
+        }
+        # Durable records keyed by the reviewer identity must also be cleared.
+        mcp_session_state.save_state(
+            kind=mcp_session_state.KIND_WORKFLOW_LOAD,
+            payload={"loaded": True},
+            profile_identity="reviewer-profile",
+        )
+        mcp_session_state.save_state(
+            kind=mcp_session_state.KIND_DECISION_LOCK,
+            payload={"final_review_decision_ready": True, "ready_pr_number": 688},
+            profile_identity="reviewer-profile",
+        )
+
+    def _activate(self, target, logins):
+        with patch.object(
+            mcp_server, "get_auth_header", side_effect=[f"token p" for _ in logins]
+        ), patch.object(
+            mcp_server, "api_request", side_effect=[{"login": l} for l in logins]
+        ), patch.object(
+            mcp_server,
+            "_workspace_repository_slug",
+            return_value="Example-Org/Example-Repo",
+        ), patch.object(
+            mcp_server, "_canonical_repository_slug", return_value=(None, [])
+        ):
+            return mcp_server.gitea_activate_profile(profile_name=target)
+
+    # -----------------------------------------------------------------
+    # AC1/AC2/AC3: switch invalidates review state; re-preflight required
+    # -----------------------------------------------------------------
+    def test_switch_invalidates_review_state_and_blocks_verdict(self):
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            self._seed_contaminated_review_state()
+            res = self._activate("author-profile", ["reviewer-user", "author-user"])
+
+            self.assertTrue(res["success"])
+            self.assertTrue(res["re_preflight_required"])
+            inv = res["review_state_invalidation"]
+            self.assertEqual(inv["from_profile"], "reviewer-profile")
+            self.assertEqual(inv["to_profile"], "author-profile")
+            for item in (
+                "preflight_identity_capability",
+                "review_workflow_load",
+                "review_decision_lock",
+                "reviewer_session_lease",
+                "live_namespace_health",
+            ):
+                self.assertIn(item, inv["invalidated"])
+
+            # In-memory state cleared.
+            self.assertFalse(mcp_server._preflight_whoami_called)
+            self.assertFalse(mcp_server._preflight_capability_called)
+            self.assertIsNone(mcp_server._preflight_resolved_task)
+            self.assertIsNone(review_workflow_load._REVIEW_WORKFLOW_LOAD)
+            self.assertIsNone(mcp_server._REVIEW_DECISION_LOCK)
+            self.assertIsNone(reviewer_pr_lease.get_session_lease())
+            self.assertEqual(mcp_server._LIVE_NAMESPACE_HEALTH, {})
+            self.assertIsNotNone(mcp_server._PROFILE_SWITCH_INVALIDATION)
+
+            # Durable records keyed by the reviewer identity are gone.
+            self.assertIsNone(
+                mcp_session_state.load_state(
+                    kind=mcp_session_state.KIND_WORKFLOW_LOAD,
+                    profile_identity="reviewer-profile",
+                )
+            )
+            self.assertIsNone(
+                mcp_session_state.load_state(
+                    kind=mcp_session_state.KIND_DECISION_LOCK,
+                    profile_identity="reviewer-profile",
+                )
+            )
+
+            # A formal verdict without re-preflight fails closed.
+            reasons = mcp_server.check_review_decision_gate(
+                688, "APPROVE", final_review_decision_ready=True
+            )
+            self.assertTrue(reasons)
+
+    def test_switch_back_cannot_resurrect_stale_review_run(self):
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            self._seed_contaminated_review_state()
+            self._activate("author-profile", ["reviewer-user", "author-user"])
+            res = self._activate("reviewer-profile", ["author-user", "reviewer-user"])
+
+            self.assertTrue(res["success"])
+            # The pre-switch review run must not reappear.
+            self.assertIsNone(mcp_server._REVIEW_DECISION_LOCK)
+            self.assertIsNone(review_workflow_load._REVIEW_WORKFLOW_LOAD)
+            self.assertIsNone(reviewer_pr_lease.get_session_lease())
+            status = review_workflow_load.workflow_load_status()
+            self.assertFalse(status["workflow_load_valid"])
+            reasons = mcp_server.check_review_decision_gate(
+                688, "APPROVE", final_review_decision_ready=True
+            )
+            self.assertTrue(reasons)
+
+    def test_same_profile_reactivation_keeps_state(self):
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            self._seed_contaminated_review_state()
+            res = self._activate("reviewer-profile", ["reviewer-user", "reviewer-user"])
+            self.assertTrue(res["success"], res)
+            self.assertNotIn("review_state_invalidation", res)
+            self.assertIsNotNone(mcp_server._REVIEW_DECISION_LOCK)
+            self.assertTrue(mcp_server._preflight_whoami_called)
+
+    def test_clean_repreflight_after_switch_allows_gate(self):
+        with patch.dict(os.environ, self._env("reviewer-profile"), clear=True):
+            self._seed_contaminated_review_state()
+            self._activate("author-profile", ["reviewer-user", "author-user"])
+            self._activate("reviewer-profile", ["author-user", "reviewer-user"])
+
+            # Re-establish the full reviewer preflight under the new profile.
+            mcp_server.record_preflight_check("whoami")
+            mcp_server.record_preflight_check(
+                "capability", resolved_role="reviewer", resolved_task="review_pr"
+            )
+            mcp_server.init_review_decision_lock("dadeschools", "review_pr")
+            lock = mcp_server._load_review_decision_lock()
+            self.assertIsNotNone(lock)
+            lock.update(
+                {
+                    "final_review_decision_ready": True,
+                    "ready_pr_number": 688,
+                    "ready_action": "APPROVE",
+                    "ready_remote": "dadeschools",
+                    "ready_org": "Example-Org",
+                    "ready_repo": "Example-Repo",
+                }
+            )
+            mcp_server._save_review_decision_lock(lock)
+
+            with patch.object(
+                mcp_server, "_review_workflow_load_gate_reasons", return_value=[]
+            ):
+                reasons = mcp_server.check_review_decision_gate(
+                    688,
+                    "APPROVE",
+                    final_review_decision_ready=True,
+                    remote="dadeschools",
+                )
+            self.assertEqual(reasons, [])
+
+    # -----------------------------------------------------------------
+    # AC4: namespace provenance reporting + fail-closed mismatch
+    # -----------------------------------------------------------------
+    def test_namespace_provenance_mismatch_detection(self):
+        prov = mcp_namespace_health.namespace_provenance(
+            task="review_pr",
+            active_profile="reviewer-profile",
+            env={"GITEA_MCP_NAMESPACE": "gitea-author"},
+        )
+        self.assertTrue(prov["mismatch"])
+        self.assertEqual(prov["required_namespace"], "gitea-reviewer")
+
+        prov_ok = mcp_namespace_health.namespace_provenance(
+            task="review_pr",
+            active_profile="reviewer-profile",
+            env={"GITEA_MCP_NAMESPACE": "gitea-reviewer"},
+        )
+        self.assertFalse(prov_ok["mismatch"])
+
+        prov_unknown = mcp_namespace_health.namespace_provenance(
+            task="review_pr", active_profile="reviewer-profile", env={}
+        )
+        self.assertIsNone(prov_unknown["configured_namespace"])
+        self.assertFalse(prov_unknown["mismatch"])
+        self.assertEqual(prov_unknown["namespace_source"], "unknown")
+
+    @patch("mcp_server.api_request", return_value={"login": "reviewer-user"})
+    @patch("mcp_server.get_auth_header", return_value="token reviewer-pass")
+    def test_whoami_reports_namespace_provenance(self, _auth, _api):
+        env = self._env("reviewer-profile")
+        env["GITEA_MCP_NAMESPACE"] = "gitea-reviewer"
+        with patch.dict(os.environ, env, clear=True):
+            res = mcp_server.gitea_whoami(remote="dadeschools")
+        prov = res["namespace_provenance"]
+        self.assertEqual(prov["configured_namespace"], "gitea-reviewer")
+        self.assertEqual(prov["active_profile"], "reviewer-profile")
+        self.assertFalse(prov["mismatch"])
+
+    @patch("mcp_server.api_request", return_value={"login": "reviewer-user"})
+    @patch("mcp_server.get_auth_header", return_value="token reviewer-pass")
+    def test_resolve_fails_closed_on_namespace_mismatch(self, _auth, _api):
+        env = self._env("reviewer-profile")
+        env["GITEA_MCP_NAMESPACE"] = "gitea-author"
+        with patch.dict(os.environ, env, clear=True):
+            res = mcp_server.gitea_resolve_task_capability(
+                task="review_pr", kwargs="{}", remote="dadeschools"
+            )
+        self.assertFalse(res["allowed_in_current_session"])
+        self.assertTrue(res["namespace_provenance"]["mismatch"])
+        self.assertTrue(
+            any("namespace" in g for g in res["task_role_guidance"])
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()