fix: persist room operation cancellation across lost admission acknowledgments

tests/unit/test_chat_runs_limits.py

@@ -31,3 +31,26 @@ def test_event_capacity_failure_persists_stop_and_reserved_terminal(tmp_path):
         assert store.events(owner['id'],rid)[-1]['event'] == 'done'
         accounts.close()
     asyncio.run(scenario())
+
+
+def test_cancel_key_before_admission_never_starts_and_is_owner_scoped(tmp_path):
+    async def scenario():
+        accounts = Accounts(str(tmp_path/'cancel.db'))
+        user = accounts.create('test','Test','admin','offline-test-password')
+        other = accounts.create('other','Other','user','offline-test-password')
+        token, _ = accounts.issue_session(user['id'],3600,user['password_hash'])
+        store = ChatStore(accounts)
+        cid = store.create_conversation(user['id'])['id']
+        runs = ChatRuns(accounts,store,adapter=object())
+        assert await runs.cancel_operation(user['id'],cid,'uncertain-key') == {'ok':True,'run':None}
+        operation = await runs.send(user['id'],cid,token,content='Hi',idempotency_key='uncertain-key')
+        assert operation['run']['status'] == 'cancelled'
+        assert runs.tasks == {}
+        assert (await runs.send(user['id'],cid,token,content='Hi',idempotency_key='uncertain-key'))['run']['id'] == operation['run']['id']
+        try:
+            await runs.cancel_operation(other['id'],cid,'uncertain-key')
+            assert False, 'Foreign owner cancellation was accepted'
+        except KeyError:
+            pass
+        accounts.close()
+    asyncio.run(scenario())