A selfbot (user token) cannot auto-detect other members' camera/share
(no VOICE_STATE_UPDATE for others, 403 on member fetch). The only
selfbot-viable path to capture another member's SCREEN SHARE is an
operator-initiated STREAM_WATCH (gateway op 20, not gated on bot-vs-user).
Add video:watch / video:unwatch Redis commands routed via the existing
command handler to startStreamWatch/stopStreamWatch, which then does the
DAVE handshake + per-burst MP4 segmentation + DB insert + Tele upload
(already implemented in streamWatchReceiver).
- new VideoHandler (command-handler/video.handler.ts)
- register video:watch / video:unwatch in handler-registry + CommandHandler
- command constants COMMAND_VIDEO_WATCH / COMMAND_VIDEO_UNWATCH
- resolve active voice channel from voice controller + client cache
- 8 unit tests (videoHandler.test.ts)
- biome fixes for pre-existing test import ordering
All green: typecheck, build, lint (174 files), 200 tests.