feat: add high quality playback

[Priveetee]

Summary

• Add an opt-in high quality playback setting backed by the user settings API.
• Use the backend DASH manifest for YouTube high quality playback with fallback on player errors.
• Add DASH codec and quality selectors for H.264, VP9, and AV1 tracks.
• Run Vite tool binaries under Bun and update Tailwind packages.

Validation

• bun run check
• bun run build
• NODE_OPTIONS="--trace-deprecation" bun run build
• bun run knip
• bun run sherif
• git diff --check
• Verified /api/streams/manifest exposes AV1 for KLuTLF3x9sA and 49Dy0nvs7Lw