fix(worktree): address PR review — test assertion, dry-run sentinel, git timeouts

- Update allProjects test expectation to match [parent, composite] (matches JSDoc + callers in ContextBuilder/context handlers).
- Replace string-matched __DRY_RUN_ROLLBACK__ sentinel with dedicated DryRunRollback class to avoid swallowing unrelated errors.
- Add 5000ms timeout to spawnSync git calls in WorktreeAdoption and ProcessManager so worker startup can't hang on a stuck git process.
- Drop unreachable break after process.exit(0) in adopt case.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/services/worker-service.ts

@@ -1235,7 +1235,6 @@ async function main() {
         console.log(`  ! ${err.worktree}: ${err.error}`);
       }
       process.exit(0);
-      break;
     }
 
     case '--daemon':