feat(admin): attach a real PersistedRoomData save to a baked RRO sub-room

POST rooms/{id}/subrooms/{sub}/blob/upload (multipart file, ?mode=full|
basics) rewrites a save from ANY client version for this room —
activity_id → the room's LocationReplicationId, output_log / sub_room_id /
unknown-to-2023 fields dropped, header versions clamped to the 2023
maxima; "basics" additionally keeps only the game-role (field 50) and
game-rule (40/41) objects and strips the circuit payloads, since a newer
CircuitsV2 graph is rejected by the client's own CV2 gate regardless —
stores it as room_{id}_upload_*.dat, records the RoomDataBlobs row and
points the sub-room (and room, for sub-room 0) at it. The CDN's RRO role
overlay + clamp then apply on serve exactly as for Rec Center's saved
blob. Admin SPA: "Upload save" file input + mode select on the Sub-rooms
tab for baked originals.

Purpose: A/B a genuine custom-Rec-Royale save (Squads chip room) against
the generated stub, whose four objects the client currently fails to
instantiate (NullReferenceException in CreationManager.InstantiateRequest-
ForViewData, then "Not object found for Persistence View").
Test: Uploading_a_real_save_attaches_it_to_the_room_rewritten_for_2023.

docs/recroom-2023-room-save.md

@@ -190,6 +190,11 @@ Solos `983db81a68927f419edb0daf1243e93e`, Squads
 Configuration chip, optional — `GameConfigurationTool` falls back to its
 baked asset. The stub emits the wrapper chip for the two Rec Royale rooms.
 
+Attaching a real save: `POST api/admin/v1/rooms/{id}/subrooms/{sub}/blob/upload`
+(multipart `file`, `?mode=basics|full`) rewrites any-version
+`PersistedRoomData` for the room — see `docs/admin.md` → "Upload save".
+Used to A/B a generated stub against a genuine custom-Rec-Royale save.
+
 Admin switch: `POST api/admin/v1/rooms/{id}/subrooms/{sub}/blob/enable`
 stamps `RoomService.SyntheticDefaultRoomDataBlobName(id)` on the scene and
 room; `.../blob/reset` clears it. See `docs/admin.md` → "RRO room data