tldv Meeting Downloader

1. Injects a Download button next to "Copy link" on any tldv.io meeting page 2. Fetches meeting metadata and the obfuscated HLS playlist from tldv's API 3. Decodes the playlist (tldv uses a Caesar cipher on segment URLs) 4. Downloads all `.ts` segments concurrently with live progress 5. Remuxes segments into MP4 using ffmpeg.wasm (stream copy, no re-encoding) 6. Triggers a standard browser file download as YYYY-MM-DD_Meeting-Name.mp4 Public meetings work without login. Private meetings use your existing tldv session (Firebase auth token).