apply codex code review: fix useEffect refetch loops, dead routes, subtitle job_type leftovers

All ack'd as real bugs:

frontend
- AudioDetailPage / SubtitleDetailPage / PathsPage / ScanPage /
  SubtitleListPage / ExecutePage: load() was a fresh function reference
  every render, so 'useEffect(() => load(), [load])' refetched on every
  render. Wrap each in useCallback with the right deps ([id], [filter],
  or []).
- SetupPage: langsLoaded was useState; setting it inside load() retriggered
  the same effect → infinite loop. Switch to useRef. Also wrap saveJellyfin/
  Radarr/Sonarr in async fns so they return Promise<void> (matches the
  consumer signatures, fixes the latent TS error).
- DashboardPage: redirect target /setup doesn't exist; the route is
  /settings.
- ExecutePage: <>...</> fragment with two <tr> children had keys on the
  rows but not on the fragment → React reconciliation warning. Use
  <Fragment key>. jobTypeLabel + badge variant still branched on the
  removed 'subtitle' job_type — relabel to 'Audio Transcode' / 'Audio
  Remux' and use 'manual'/'noop' variants.

server
- review.ts + scan.ts: parseLanguageList helper catches JSON errors and
  enforces array-of-strings shape with a fallback. A corrupted config
  row would otherwise throw mid-scan.

server/api/review.ts

@@ -11,7 +11,21 @@ const app = new Hono();
 // ─── Helpers ──────────────────────────────────────────────────────────────────
 
 function getSubtitleLanguages(): string[] {
-	return JSON.parse(getConfig("subtitle_languages") ?? '["eng","deu","spa"]');
+	return parseLanguageList(getConfig("subtitle_languages"), ["eng", "deu", "spa"]);
+}
+
+function getAudioLanguages(): string[] {
+	return parseLanguageList(getConfig("audio_languages"), []);
+}
+
+function parseLanguageList(raw: string | null, fallback: string[]): string[] {
+	if (!raw) return fallback;
+	try {
+		const parsed = JSON.parse(raw);
+		return Array.isArray(parsed) ? parsed.filter((v): v is string => typeof v === "string") : fallback;
+	} catch {
+		return fallback;
+	}
 }
 
 function countsByFilter(db: ReturnType<typeof getDb>): Record<string, number> {
@@ -114,7 +128,7 @@ function reanalyze(db: ReturnType<typeof getDb>, itemId: number, preservedTitles
 		.prepare("SELECT * FROM media_streams WHERE item_id = ? ORDER BY stream_index")
 		.all(itemId) as MediaStream[];
 	const subtitleLanguages = getSubtitleLanguages();
-	const audioLanguages: string[] = JSON.parse(getConfig("audio_languages") ?? "[]");
+	const audioLanguages = getAudioLanguages();
 	const analysis = analyzeItem(
 		{ original_language: item.original_language, needs_review: item.needs_review, container: item.container },
 		streams,
@@ -186,7 +200,7 @@ function recomputePlanAfterToggle(db: ReturnType<typeof getDb>, itemId: number):
 	}[];
 
 	const origLang = item.original_language ? normalizeLanguage(item.original_language) : null;
-	const audioLanguages: string[] = JSON.parse(getConfig("audio_languages") ?? "[]");
+	const audioLanguages = getAudioLanguages();
 
 	// Re-assign target_index based on current actions
 	const decWithIdx = decisions.map((d) => ({