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>

package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "start": "node --import tsx src/server.ts",
     "dev": "node --import tsx --watch src/server.ts",
-    "check": "tsc"
+    "check": "tsc",
+    "test": "node --import tsx --test test/*.test.ts"
   },
   "dependencies": {
     "cookie-session": "^2.1.0",