fix: isolate immutable session context tests (#714)

tests/conftest.py

@@ -26,6 +26,14 @@ def _reset_mutation_authority(monkeypatch):
     Pin ``default_state_dir`` / ``DEFAULT_STATE_DIR`` to a per-test temp dir
     so durable load/save never touches host state even after env clears.
     """
+    import session_context_binding as session_ctx
+
+    # Each pytest item is an independent logical MCP session. Reset both before
+    # and after the item; the post-yield reset is in a finally block so an
+    # assertion, exception, or unittest teardown failure cannot pollute the
+    # next item. Production code has no automatic per-call reset path.
+    session_ctx._reset_session_context_for_testing()
+
     for env_key in [
         "GITEA_SESSION_PROFILE_LOCK",
         "GITEA_ACTIVE_WORKTREE",
@@ -80,9 +88,15 @@ def _reset_mutation_authority(monkeypatch):
     try:
         import mcp_server
     except Exception:
-        _state_tmp.cleanup()
-        yield
+        try:
+            yield
+        finally:
+            session_ctx._reset_session_context_for_testing()
+            _state_tmp.cleanup()
         return
+    import gitea_config
+
+    monkeypatch.setattr(gitea_config, "_active_profile_override", None)
     monkeypatch.setattr(mcp_server, "_MUTATION_AUTHORITY", None)
     monkeypatch.setattr(mcp_server, "_IDENTITY_CACHE", {})
     monkeypatch.setattr(mcp_server, "_REVIEW_DECISION_LOCK", None)
@@ -113,19 +127,23 @@ def _reset_mutation_authority(monkeypatch):
         capability_stop_terminal.clear()
     except Exception:
         pass
-    yield
     try:
-        import capability_stop_terminal
-        capability_stop_terminal.clear()
-    except Exception:
-        pass
-    try:
-        import review_workflow_load
-        review_workflow_load._REVIEW_WORKFLOW_LOAD = None
-    except Exception:
-        pass
-    try:
-        mcp_server._REVIEW_DECISION_LOCK = None
-    except Exception:
-        pass
-    _state_tmp.cleanup()
+        yield
+    finally:
+        try:
+            import capability_stop_terminal
+            capability_stop_terminal.clear()
+        except Exception:
+            pass
+        try:
+            import review_workflow_load
+            review_workflow_load._REVIEW_WORKFLOW_LOAD = None
+        except Exception:
+            pass
+        try:
+            mcp_server._REVIEW_DECISION_LOCK = None
+        except Exception:
+            pass
+        gitea_config._active_profile_override = None
+        session_ctx._reset_session_context_for_testing()
+        _state_tmp.cleanup()