Ensure enrichment data is always available on title pages

Cast, availability, recommendations, colors, and trailers were missing
on first load because importTitle fire-and-forgot enrichment tasks.
getTitleWithChildren now calls ensureEnriched() to backfill any missing
data before rendering — works for new imports, old titles, and shells.

Also removes the awaitEnrichment option from importTitle (redundant now)
and optimizes DB queries: reuses already-read data for existence checks,
caches fetchSeasonsFromDb result, and skips re-reads when no backfill ran.

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

app/api/titles/resolve/route.ts

@@ -38,7 +38,7 @@ export async function POST(req: NextRequest) {
   }
 
   try {
-    const title = await importTitle(tmdbId, type, { awaitEnrichment: true });
+    const title = await importTitle(tmdbId, type);
     return NextResponse.json({ id: title?.id });
   } catch {
     return NextResponse.json(