split audio/subtitle concerns, remove docker-in-docker, add per-node path mapping

- install ffmpeg in dockerfile (fixes exit code 127)
- buildCommand() now audio-only remux, no subtitle extraction
- add unapprove endpoint + ui button for approved items
- add batch extract-all subtitles endpoint + ui button
- audio detail page shows only video+audio streams
- remove global movies_path/series_path config, add per-node path mapping
- remove docker-in-docker command building (buildDockerCommand, buildDockerExtractOnlyCommand)
- ssh execution translates /movies/ and /series/ to node-specific paths
- remove media paths section from setup page
- add unraid-template.xml

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/api/setup.ts

@@ -83,15 +83,6 @@ app.post('/subtitle-languages', async (c) => {
 	return c.json({ ok: true });
 });
 
-app.post('/paths', async (c) => {
-	const body = await c.req.json<{ movies_path?: string; series_path?: string }>();
-	const moviesPath = (body.movies_path ?? '').trim().replace(/\/$/, '');
-	const seriesPath = (body.series_path ?? '').trim().replace(/\/$/, '');
-	setConfig('movies_path', moviesPath);
-	setConfig('series_path', seriesPath);
-	return c.json({ ok: true });
-});
-
 app.post('/clear-scan', (c) => {
 	const db = getDb();
 	db.prepare('DELETE FROM media_items').run();