Implement full Couch Potato movie & TV tracking app

Add all 10 milestones: Drizzle ORM + SQLite database with WAL mode,
Better Auth email/password authentication, TMDB API integration for
search and metadata import, TV season/episode caching, user tracking
(watchlist/status/watches/ratings with auto-transitions), discovery
feeds (continue watching, library, recommendations), US streaming
availability via TMDB providers, background job scheduler with
instrumentation hook, and dark cinema-themed frontend with DM Serif
Display + DM Sans typography and amber accent design system.

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

app/api/auth/[...all]/route.ts

@@ -0,0 +1,4 @@
+import { toNextJsHandler } from "better-auth/next-js";
+import { auth } from "@/lib/auth/server";
+
+export const { GET, POST } = toNextJsHandler(auth);