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>

test/fixtures/standings.json

@@ -0,0 +1,66 @@
+[
+ {
+  "Team": {
+   "Players": [
+    {
+     "Name": "Alice Archer",
+     "DisplayName": "alice",
+     "Username": "alice"
+    }
+   ]
+  },
+  "RoundNumber": 1,
+  "Points": 3,
+  "MatchWins": 1,
+  "MatchDraws": 0,
+  "MatchLosses": 0
+ },
+ {
+  "Team": {
+   "Players": [
+    {
+     "Name": "Bob Baker",
+     "DisplayName": "bobb",
+     "Username": "bobb"
+    }
+   ]
+  },
+  "RoundNumber": 1,
+  "Points": 0,
+  "MatchWins": 0,
+  "MatchDraws": 0,
+  "MatchLosses": 1
+ },
+ {
+  "Team": {
+   "Players": [
+    {
+     "Name": "Alice Archer",
+     "DisplayName": "alice",
+     "Username": "alice"
+    }
+   ]
+  },
+  "RoundNumber": 2,
+  "Points": 6,
+  "MatchWins": 2,
+  "MatchDraws": 0,
+  "MatchLosses": 0
+ },
+ {
+  "Team": {
+   "Players": [
+    {
+     "Name": "Bob Baker",
+     "DisplayName": "bobb",
+     "Username": "bobb"
+    }
+   ]
+  },
+  "RoundNumber": 2,
+  "Points": 1,
+  "MatchWins": 0,
+  "MatchDraws": 1,
+  "MatchLosses": 1
+ }
+]