Import Melee matches exports, add tests and local podman stack

- Parse Melee matches exports (one round per file, byes, null GameWins);
  one import form detects matches vs standings exports. Re-importing a
  round replaces just that round and keeps entered decks.
- Per-player deck entry for sessions scored from matches.
- node:test suite with anonymised fixtures; lockfile.
- scripts/local.sh runs the compose stack under podman with its own
  .env.local, project name and volume.
- README and CLAUDE.md docs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -0,0 +1,31 @@
+# MTG league tracker
+
+Leaderboard and results dashboard for a Magic league run on melee.gg. See `CLAUDE.md` for design notes.
+
+## Run
+```
+cp .env.example .env     # fill in DB_PASSWORD, SECRET_KEY (openssl rand -hex 32), ADMIN_PASSWORD (10+ chars)
+docker compose up -d --build
+```
+Listens on `${BIND_ADDR:-127.0.0.1}:${HOST_PORT:-8888}`. Put a reverse proxy in front and set `COOKIE_SECURE=true` once on https.
+Sub-path hosting: set `BASE_PATH=/mtg` and proxy with Caddy `handle_path /mtg/*`.
+
+## Develop
+```
+npm install
+npm test          # parser + standings tests
+npm run check     # type-check
+DATABASE_URL=postgres://... SECRET_KEY=... ADMIN_PASSWORD=... npm run dev
+```
+Whole stack locally with podman (own `.env.local` with generated secrets, own project/volume, port 8889):
+```
+scripts/local.sh up      # build + start, prints URL and admin password
+scripts/local.sh logs | ps | down
+scripts/local.sh reset   # down and delete the local database
+```
+Needs `podman compose` (podman 4.7+ with docker-compose or podman-compose) and the user socket:
+`systemctl --user enable --now podman.socket`.
+
+## Using it
+Admin login, create a league (set how many top sessions count), add a session per night, then upload the Melee
+matches export (one per round) or standings export on the session page, and set each player's deck.