## Why
Answers collected by `request_user_input` can change what the user authorizes, but post-tool hooks may replace or reject the tool output that Guardian normally sees.
## What changed
- Record bounded, host-observed answers before post-tool hooks run and provide them as trusted evidence to synchronous and asynchronous Guardian reviews.
- Include root-thread answers in worker review context.
- Count successful answers as authorization changes so earlier review evidence becomes stale, while ignoring empty or unrelated answers.
## Testing
Add coverage for allowed and denied stale reviews, empty and oversized answers, hook-modified output, and root-to-worker propagation.
GitOrigin-RevId: 970c52e40338ecd057c7cd2a69d04b06e97cd068