refactor(agent): complete inbox lifecycle migration

packages/compact/command-compact/tests/command-compact.spec.ts

@@ -175,6 +175,7 @@ describe('/compact human command', () => {
 
   it.each([
     ['busy', 'Compaction is unavailable because this process has an active compaction, or the agent is not idle.'],
+    ['cancelled', 'Compaction cancelled.'],
     ['changed', 'The history selected for compaction changed before it could be replaced. The conversation is unchanged; the attempt is recorded in the session log.'],
     ['summary', 'Compaction could not produce a useful summary. The conversation is unchanged; the attempt is recorded in the session log.'],
     ['commit', 'Compaction did not finish cleanly; some session history may have changed. Inspect the current session state before retrying.'],