Subtitle auto-sync, rewritten

Auto-sync

It used to match the cues against raw loudness, so a door slam outranked a spoken line and the subtitles drifted towards the music. It now matches on speech - how far the audio sits above the room, normalised per film.

• Accepts a fit only when it clearly beats every other one, instead of guessing.
• Lands inside 40 ms, and the delay reads to two decimals.
• Searches ±3 minutes, up from ±90 seconds, and falls back to listening to the whole film when the last twenty minutes are not conclusive.
• When it still cannot tell, it offers its best guess as one button instead of giving up.
• Still fixes 23.976 / 24 / 25 fps mismatches, now only when it is sure.

Player

• Subtitles lift above the control bar whenever the chrome is up, not only when a panel is open.
• Real tooltips on the player buttons - and mpv no longer paints over them.
• The volume knob stays inside the rail at 100%.
• YouTube trailers scale correctly at any interface scale.

Library

• Favourites, Watchlist and History filter by title, sort by recency, title, year or rating, and split into All / Movies / TV / Anime.
• The controls bar measures its own width instead of trusting a breakpoint, so filters stop crowding each other at middling window widths.

Fixes

• Roboto actually ships now - the desktop builds had been falling back to the system sans-serif.
• A missing appindicator library no longer takes the whole app down at startup.