migrate subrooms to own storage

apps/rooms/migrations/0007_subrooms.sql

@@ -0,0 +1,55 @@
+-- Subrooms as first-class entities. In the original game a subroom has its own
+-- globally-unique, autoincrementing `SubRoomId` (minted from a single sequence, not
+-- per-room), so they can't live inside the room JSON blob — cloning/dorm creation
+-- would otherwise reuse ids and collide across rooms. This moves them into their own
+-- `subroom` table keyed by an AUTOINCREMENT `sub_room_id`, backfills from each room's
+-- embedded `SubRooms`, and drops `SubRooms` from the room blob. Rooms re-embed their
+-- `SubRooms` array on read. Generated from packages/domain/src/rooms-db.ts
+-- (SUBROOM_SCHEMA_DDL) — keep in sync.
+
+CREATE TABLE IF NOT EXISTS subroom (
+  sub_room_id INTEGER PRIMARY KEY AUTOINCREMENT,
+  room_id INTEGER NOT NULL,
+  data TEXT NOT NULL
+  );
+CREATE INDEX IF NOT EXISTS idx_subroom_room ON subroom (room_id);
+
+-- Backfill. The live blob already contains collisions (the bug this migration fixes:
+-- every dorm carries SubRoomId 1, clones reuse per-room ids), so we can't preserve all
+-- ids. We keep the FIRST occurrence of each distinct SubRoomId at its original id (so the
+-- seeded rooms keep their canonical ids) and mint fresh globally-unique ids for the rest.
+
+-- 1) First occurrence of each non-null SubRoomId keeps its id (lowest room_id wins).
+INSERT INTO subroom (sub_room_id, room_id, data)
+  SELECT sid, room_id, data FROM (
+    SELECT
+      CAST(json_extract(je.value, '$.SubRoomId') AS INTEGER) AS sid,
+      r.room_id AS room_id,
+      je.value AS data,
+      ROW_NUMBER() OVER (
+        PARTITION BY json_extract(je.value, '$.SubRoomId')
+        ORDER BY r.room_id
+      ) AS rn
+    FROM room r, json_each(r.data, '$.SubRooms') je
+  )
+  WHERE rn = 1 AND sid IS NOT NULL;
+
+-- 2) Everything else (the duplicates, and any null ids) gets a fresh autoincrement id.
+--    Inserting the explicit ids above advanced sqlite_sequence, so these continue past
+--    the highest kept id and never collide.
+INSERT INTO subroom (room_id, data)
+  SELECT room_id, data FROM (
+    SELECT
+      CAST(json_extract(je.value, '$.SubRoomId') AS INTEGER) AS sid,
+      r.room_id AS room_id,
+      je.value AS data,
+      ROW_NUMBER() OVER (
+        PARTITION BY json_extract(je.value, '$.SubRoomId')
+        ORDER BY r.room_id
+      ) AS rn
+    FROM room r, json_each(r.data, '$.SubRooms') je
+  )
+  WHERE NOT (rn = 1 AND sid IS NOT NULL);
+
+-- Single source of truth: drop the now-migrated SubRooms array from the room blob.
+UPDATE room SET data = json_remove(data, '$.SubRooms');