## Why
Streaming `bio_policy` failures were classified as generic invalid requests, losing their policy-specific classification.
## What changed
- Add `BioPolicy` errors across the API and core protocol, recognizing streaming failures and HTTP 400 responses, including wrapped WebSocket errors.
- Preserve server messages and use a biological-risk fallback when the message is missing or blank.
- Treat bio policy errors as non-retryable in core and guardian handling, and classify them in diagnostics and telemetry.
- Map `BioPolicy` to `other` in the app-server v2 protocol.
## Testing
Add coverage for error classification, message preservation and fallbacks, HTTP and wrapped WebSocket responses, guardian retry decisions, and app-server conversion. Extend the core integration test to verify that bio policy failures emit a typed error and complete the turn after a single request.
GitOrigin-RevId: 78c2647e8fc8f80297cb8a23fff06ab141099632
fa8cf44985