Add Docker packaging and migrate from better-sqlite3 to libsql

Docker self-hosting support:
- Dockerfile (multi-stage Alpine build with tini init)
- docker-compose.yml with named volume for SQLite persistence
- /api/health endpoint for container health checks
- Auto-migration on startup via drizzle-orm/libsql/migrator
- Graceful shutdown (SIGTERM stops scheduler, closes DB)
- Next.js standalone output mode for minimal image size

Database driver migration (better-sqlite3 → @libsql/client):
- Eliminates native C++ compilation, enabling Alpine Docker images
- All DB queries converted from sync to async across services and routes
- DATABASE_URL now uses libsql file: prefix format
- drizzle.config.ts dialect changed to turso for libsql support
- Initial migration files generated in drizzle/

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

app/api/feed/stats/route.ts

@@ -27,7 +27,7 @@ export async function GET() {
   weekStart.setDate(now.getDate() - (dayOfWeek === 0 ? 6 : dayOfWeek - 1));
   weekStart.setHours(0, 0, 0, 0);
 
-  const [moviesThisMonth] = db
+  const [moviesThisMonth] = await db
     .select({ count: sql<number>`count(*)` })
     .from(userMovieWatches)
     .where(
@@ -38,7 +38,7 @@ export async function GET() {
     )
     .all();
 
-  const [episodesThisWeek] = db
+  const [episodesThisWeek] = await db
     .select({ count: sql<number>`count(*)` })
     .from(userEpisodeWatches)
     .where(
@@ -49,13 +49,13 @@ export async function GET() {
     )
     .all();
 
-  const [librarySize] = db
+  const [librarySize] = await db
     .select({ count: sql<number>`count(*)` })
     .from(userTitleStatus)
     .where(eq(userTitleStatus.userId, userId))
     .all();
 
-  const [completedCount] = db
+  const [completedCount] = await db
     .select({ count: sql<number>`count(*)` })
     .from(userTitleStatus)
     .where(