fix(cloud-task): recover queued messages after sandbox stops

[tatoalo]

Problem

Cloud task runs can remain in_progress after the backing sandbox has stopped. When the renderer is disconnected in that state, a follow-up message is queued behind the agent-ready guard, but no fresh run_started or turn_complete event arrives to drain it.

Changes

• propagate task-run state.sandbox_alive through cloud task watcher status and snapshot updates
• refetch run detail during retry for already-hydrated watchers so reconnects surface the current sandbox liveness
• force-drain a stranded queued cloud message when the server reports the sandbox is stopped and the local session is disconnected or errored

[greptile-apps]

_{Reviews (1): Last reviewed commit: "fix(cloud-task): recover queued messages..." | Re-trigger Greptile}

[github-actions]

React Doctor found no issues in the changed files. 🎉

_{Reviewed by React Doctor for commit 15e43ae.}

[github-actions]

The bot comment about missing coverage for the "error" status was already addressed in the current diff — the new integration test uses it.each(["disconnected", "error"]) to cover both cases. The core logic is well-guarded: the force-flush path only fires when sandboxAlive === false AND the session is disconnected/error AND not prompt-pending, which is a safe, narrowly scoped recovery path. Interface additions are optional and backward-compatible, and the retry() return-type change to Promise<void> is non-breaking for existing callers.

[greptile-apps]

_{Reviews (2): Last reviewed commit: "test(cloud-task): cover error status san..." | Re-trigger Greptile}

New commits pushed (delta classified non_trivial_delta) — stamphog approval dismissed; re-review running automatically.

[github-actions]

No showstoppers. The sandbox-stopped recovery path is narrowly guarded (sandboxAlive===false AND disconnected/error AND not prompt-pending AND reentrancy lock), the interface additions are optional and backward-compatible, and the previously flagged missing coverage for the "error" status is addressed in the current diff via it.each.

New commits pushed (delta classified non_trivial_delta) — stamphog approval dismissed; re-review running automatically.

[github-actions]

Narrowly scoped bug fix with solid guards: the force-flush path fires only when sandboxAlive === false AND the session is disconnected/error AND not prompt-pending, with the existing reentrancy lock preventing double-fires. Interface additions are optional and backward-compatible, the retry() async signature change is safe for void callers, and the previously flagged missing "error" status coverage is addressed via it.each.