Lohnt sich dein eigenes Letterboxd?

Build a local-first personal film diary web app. Single user, no accounts, no cloud, no telemetry.

Stack, non-negotiable:
- Next.js 15 with the App Router, TypeScript, Tailwind.
- SQLite via better-sqlite3, one file at ./data/diary.db, schema created on first run.
- No auth, no external services except TMDB for metadata.

Secrets:
- .env.local with TMDB_API_KEY. Commit .env.example only. Fail loudly with a readable message if the key is missing.

Data model:
- films: tmdb_id (primary key), title, year, director, runtime, poster_path, overview, cached_at.
- entries: id, tmdb_id, watched_on (date), rating (0.5 to 5 in half steps, nullable), review (text, nullable), rewatch (boolean), liked (boolean), created_at.
- watchlist: tmdb_id, added_at, note.

Features in scope:
- Search box that hits TMDB search, shows posters and years, one click to log. Cache the film row locally so the app works offline for anything already logged.
- Log form: watched date defaults to today, half-star rating widget, review textarea, rewatch and liked toggles.
- Diary view grouped by month, newest first, poster grid plus compact list toggle.
- Film detail page: local metadata, every entry you have for it, rating history.
- Watchlist page with add from search and a one-click promote to a diary entry.
- Stats page: films per year and per month, rating distribution histogram, top directors by count, total runtime in hours and days, longest streak of consecutive days with a log.
- CSV import that accepts the Letterboxd export format (Name, Year, Watched Date, Rating, Review, Rewatch) and matches to TMDB with a manual disambiguation queue for anything ambiguous.
- CSV export of everything.

Explicitly out of scope: any social features, follower graphs, comments, aggregate ratings, streaming availability, mobile apps, push notifications, deployment config.

Deliver: working app, README with setup in under five commands, seed script that inserts three sample entries so the stats page is not empty on first load.