What does browserSupportedMimes mean?

browserSupportedMimes in lib/models/audios.ts and lib/models/videos.ts reads as a claim about what a browser can decode. It is not one, and some of what it lists no engine claims:

Nothing is broken by that. The list decides which files the viewer offers to open; the handler then either plays the bytes or reports an error, and a media element reads the bytes rather than the declared type. #45 measured that end of it: one WAV served as audio/wav, audio/vnd.wave, audio/x-wav and application/octet-stream played in both engines, though canPlayType answers "no" for audio/vnd.wave.

So the question is what the list is meant to be, and the name should then say it:

• If it is what we route to the handler, then handledMimes or similar is the honest name, and entries like audio/vorbis are harmless but pointless: vorbis is a codec inside audio/ogg, not a container type a file carries.
• If it is what we expect to play, then it needs trimming, and that is a behaviour change for anyone whose files carry those types today.

Worth deciding once for both handlers rather than per pull request.

Read browserSupportedMimes in lib/models/audios.ts and lib/models/videos.ts, then review the behavior measured in issue #45. Clarify whether the lists describe routed file types or expected playback types, and agree on one name and policy for both handlers. Done means the scope and any behavior change are decided before implementation.