[Linuxuser67]

Three compounding drops, one priority order (pinned HLS, direct splits, single-part adoption, HLS preset) extracted into a tested plan_streams:

• TikTok: Unknown-typed sparse mp4s now adopt even when the page also lists a separate audio track (gating keys off the missing side, not audio absence). Satisfied audio-only requests and full split pairs are untouched.
• x.com: a dialog-pinned HLS id resolves before the muxed adoption, so the pin can no longer be dropped by the HTTPS-only lookup and then shadowed. The HLS preset stays last-resort, so no-pin precedence (muxed over HLS) is unchanged.
• Dialog: the fallback quality follows the picked format's height (nearest standard bucket) instead of the global preference, so a dropped pin degrades to the chosen height. Best match keeps the preference.

Tests: 8 new (TikTok adopt, pinned-HLS priority, muxed-still-adopts, stale-pin degrade, splits untouched, audio-only untouched, HLS-preset intact, height buckets); the two bug tests fail on the old gates (negative control) and pass on the new.