ultrareview: remote task completes with empty output, findings never delivered, free review consumed

## Bug
An ultrareview (`/code-review ultra` via the deprecated `/ultrareview` alias) launched successfully, consumed **Free ultrareview 2 of 3**, and its remote task later reported `completed successfully` — but no findings were ever delivered.

## Evidence
- Launch stdout: `Ultrareview launched for refactor/tooling-simplification → main (~5-10 min, runs in the cloud)` — scope 5 files, 112 insertions, 481 deletions; tracked session: https://claude.ai/code/session_01RxyHS3TDnUbpggHLBgMsd2?from=cli
- Completion task-notification for remote task `r5puw9cn1` arrived with status `completed`, but the referenced output file exists and is **empty** (0 bytes).
- `TaskOutput`/`TaskStop` on `r5puw9cn1` both return `No task found with ID` immediately after the completion notification.
- No follow-up notification with findings ever arrived.

## Expected
Findings (or an explicit "no findings" result) delivered to the CLI session, or on failure an error status that does not consume a free review.

## Requested
The run consumed one of the account's three free ultrareviews without delivering any output — please don't count this use.

## Environment
- Claude Code CLI, darwin (macOS, Darwin 25.6.0), model claude-fable-5
- Repo under review: private GitHub repo, branch diff refactor/tooling-simplification → main (no GitHub PR; local-branch bundle form)

🤖 Filed by Claude Code on the user's behalf

Start by reproducing the `/code-review ultra` flow, including the deprecated `/ultrareview` alias, and trace the completion notification for remote task `r5puw9cn1`. Compare the empty output file with `TaskOutput` and `TaskStop` behavior. Done means findings or an explicit no-findings result reach the CLI, while failures report an error and do not consume a free ultrareview.

由索引模型根据 Issue 内容生成。