feat(media): in-channel video streaming with embedded controls

[xogium]

Summary

• Adds in-channel media file streaming with embedded playback controls (play, pause, seek, broadcast gain) directly in the connected-server view
• Replaces the separate media streaming window with a collapsible in-window video panel so the main UI stays fully usable while playback controls remain within easy reach
• Adds optional system ffmpeg pre-conversion via MediaTranscodeService when the TeamTalk SDK cannot open a file format (playback itself uses the SDK's bundled FFmpeg)

Out of scope: webcam video capture/transmission. The macOS TeamTalk 5 SDK uses 0RGB mode for camera capture, which fails on modern Mac hardware and cameras. Fixing that would require patching the SDK binary — something that feels extremely hackish and is deliberately not included in this PR.

Testing notes

I did what testing I could given that I am totally blind: keyboard navigation, VoiceOver announcements, control flow, and audio-side behavior. I have not been able to visually verify video rendering. Someone with some vision left should double-check the collapsible video panel for rendering glitches, layout issues, or other visual problems.

Test plan

• Connect to a server and stream a media file the SDK opens natively; confirm audio and video play in the in-window panel
• Collapse and expand the video panel; confirm preference persists across sessions
• Use embedded controls (play, pause, seek, broadcast gain) while navigating the rest of the main UI
• Stream a file the SDK cannot open; confirm optional ffmpeg pre-conversion path works when ffmpeg is installed
• Confirm remote users receive the stream as expected
• Visual pass: verify video frames render correctly, panel sizing/scrolling looks sane, and nothing overlaps or clips oddly
• Confirm no regression to push-to-talk / microphone preferences from the rebase onto main

Made with Cursor

[Jookia]

Xogium sent me a video showing the video playing and it visually looks correct and functional.