fix(xai-video): preserve timeout and transport error types

[EndeavorYen]

Summary

• preserve timeout failures from the xAI video wrapper as error_type="timeout"
• preserve xAI video transport failures as error_type="connection_error"
• keep unrelated wrapper failures classified as api_error
• add focused regression coverage for httpx.ReadTimeout and httpx.ConnectError

Problem

The synchronous xAI video wrapper catches exceptions raised while running the async generation/edit/extend coroutine. Today those wrapper-level exceptions are collapsed into api_error, so callers cannot distinguish a transient timeout or connection failure from a provider API response error.

That loses useful recovery signal for retry/fallback guidance and makes diagnostics less precise when the provider path fails before a structured xAI response is available.

Fix

Add a small wrapper exception classifier:

• TimeoutError and httpx.TimeoutException map to timeout
• httpx.TransportError maps to connection_error
• everything else remains api_error

The user-facing error string now includes the exception class name, which makes empty-message timeout exceptions diagnosable without changing the response schema.

Duplicate / Related Work Audit

I checked current main and GitHub issues/PRs for the same fix. I did not find an existing issue or PR that preserves xAI video wrapper timeout/transport error types.

Related but not duplicate:

• fix(video): bound xAI generation response reads #55022 / xAI video generation responses are read without a body cap #55021 bound xAI video response body reads.
• [Bug]: Generated videos are never delivered — xAI video plugin returns an ephemeral URL that is never saved locally, and video_generate is missing from gateway auto-delivery #57206 tracks xAI video delivery, ephemeral URLs, and a longer poll timeout.
• fix(agent): rebuild connection pool for socket-layer transport errors (BrokenPipe, ConnectionReset, etc.) #52226 / fix(agent): align transport-recovery error set with error classifier #52227 cover generic agent transport recovery, not the xAI video plugin wrapper.

Validation

• pytest tests/plugins/video_gen -> 46 passed
• git diff --check

[teknium1]

Thanks for the focused fix. Current main still collapses every exception escaping _run_xai_video_coroutine() into api_error at plugins/video_gen/xai/__init__.py:540-544. Generation, edit, and extend all pass through that wrapper at plugins/video_gen/xai/__init__.py:472, :496, and :512, so the PR's classifier addresses the complete synchronous wrapper boundary without changing the response shape.

Automated hermes-sweeper review.