[rooms] fix #50 room leaderboards

apps/rooms/migrations/0016_room_leaderboard.sql

@@ -0,0 +1,19 @@
+-- Per-room leaderboard definitions. Generated from packages/domain/src/rooms-db.ts
+-- (ROOM_SCHEMA_DDL) — keep in sync.
+--
+-- One row per (room, leaderboard). `leaderboard_id` is the client's slot number — small
+-- ordinals (1, 2, 3…), unique only within the room, which is why the pair is the primary
+-- key rather than the id alone. Re-posting a slot (POST /rooms/:id/leaderboards/:lid)
+-- reconfigures it in place; DELETE on the same path removes it.
+--
+-- `sort_ascending` stores the client's `sortAscending=True/False` as 1/0; `stat_format`
+-- is the client's `statFormat` int, echoed back as stored.
+
+CREATE TABLE IF NOT EXISTS room_leaderboard (
+  room_id INTEGER NOT NULL,
+  leaderboard_id INTEGER NOT NULL,
+  leaderboard_title TEXT NOT NULL,
+  stat_format INTEGER NOT NULL DEFAULT 0,
+  sort_ascending INTEGER NOT NULL DEFAULT 0,
+  PRIMARY KEY (room_id, leaderboard_id)
+  );