feat(adapters): add captions-first YouTube VideoSource
Implements ports.VideoSource against the YouTube Data API v3: ListSubscriptions (paginated), NewVideos (recent per channel), and captions-first FetchTranscript — an absent caption track yields domain.SourceNone (not an error) per ADR-007, with no audio download or speech-to-text. OAuth is written fresh on golang.org/x/oauth2 (ADR-006, distinct from ingestion's inbound MCP auth); the Google token endpoint is inlined to avoid the heavy x/oauth2/google dep. The per-connection refresh token is resolved through the SecretStore port from an opaque TokenSecretRef and is never stored on the adapter or logged. Unit-tested against an httptest server + fake SecretStore (no live googleapis egress): subscriptions list/pagination, new-video detection, captions present -> Source set, captions absent -> SourceNone no error, and secret-ref resolution failure surfacing as an error. oauth2 pinned to v0.30.0 to keep the go directive at 1.23.x (koala runner), not the v0.36 line that requires a newer toolchain. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
Claude Opus 4.8