feat(youtube): YouTube Data API v3 Core Integration (#68 - $3000 Bounty)

[sirius-016]

Summary

Complete YouTube Data API v3 integration with OAuth2, live streaming, and real-time chat for Issue #68 ($3,000).

Components

Lenses (6)

• ListVideos — Channel video listings with filtering/order
• GetVideo — Single video details (snippet/statistics/liveStreamingDetails)
• SearchVideos — Search query with type/order/pagination
• GetChannel — Channel info (subscriber count, uploads playlist)
• GetLiveChat — Real-time live chat messages with author details
• ListBroadcasts — Live broadcast listings (active/upcoming/completed)

Prisms (7)

• SendLiveChatMessage — Send messages to live chat
• CreateBroadcast — Create live broadcast events
• TransitionBroadcast — Status transition (testing/live/complete)
• DeleteBroadcast — Remove broadcast
• CreateStream — Stream config (for OBS/XSplit)
• BindBroadcast — Bind broadcast to stream
• RefreshOAuthToken — OAuth2 token refresh

Beams (1)

• AutoLiveWorkflow — One-step live stream setup (stream + broadcast + bind + transition to testing)

Tests (6) + Docs

• Unit tests for all lenses and prisms
• Livebook guide with full API documentation
• Benchee benchmarks

Acceptance Criteria

• Complete YouTube Data API v3 integration
• Live streaming setup and management
• Real-time chat monitoring and interaction
• Stream health monitoring (broadcast status transitions)
• OAuth2 token management
• Comprehensive documentation and examples

25 files total.

Closes #68

[zhaog100]

/opire try

[zhaog100]

/opire try

Claiming this bounty. Will deliver a complete implementation.