chore: integrate multiplayer code (wip)

server/relay-server/migrations/001_init.sql

@@ -0,0 +1,24 @@
+CREATE TABLE IF NOT EXISTS users (
+    id            INTEGER PRIMARY KEY AUTOINCREMENT,
+    username      TEXT    NOT NULL UNIQUE,
+    email         TEXT    NOT NULL UNIQUE,
+    password_hash TEXT    NOT NULL,
+    created_at    INTEGER NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS game_records (
+    id         INTEGER PRIMARY KEY AUTOINCREMENT,
+    game_id    TEXT    NOT NULL,
+    room_code  TEXT    NOT NULL,
+    started_at INTEGER NOT NULL,
+    ended_at   INTEGER,
+    result     TEXT
+);
+
+CREATE TABLE IF NOT EXISTS game_participants (
+    id             INTEGER PRIMARY KEY AUTOINCREMENT,
+    game_record_id INTEGER NOT NULL REFERENCES game_records(id),
+    user_id        INTEGER REFERENCES users(id),
+    player_id      INTEGER NOT NULL,
+    outcome        TEXT
+);

server/relay-server/migrations/002_participants_unique.sql

@@ -0,0 +1,3 @@
+-- Prevent duplicate participant rows if POST /games/result is called more than once.
+CREATE UNIQUE INDEX IF NOT EXISTS idx_participants_unique
+    ON game_participants(game_record_id, player_id);