Add OPENROUTER_ALLOWED_MODELS env var and GET /insights/openrouter/models
endpoint returning the curated list verbatim. Drop the live capability
precheck in hybrid mode — trust the operator's allowlist; bad ids surface
as a chat-call error.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
- Implement unit tests for PreviewClipRequest/PreviewStatusRequest serialization and deserialization.
- Add tests for PreviewDao (insert, update, batch retrieval, and status-based queries).
- Extend Actix-web integration tests for `/video/preview/status` endpoint scenarios.
- Introduce in-memory TestPreviewDao for mock database interactions.
- Update README with new config parameters for preview clips.
