fix(roms): gate sidecar caching on all active filters

The char index and rom id index sidecars are cached under a key that
encodes only user/order/grouping. is_unscoped previously excluded only
scope and search, so metadata/tag/status filters and the bool flags
applied to the query bypassed the gate: a filtered all-games request
stored a narrowed id list under the shared "all" key and later
unfiltered (or differently-filtered) requests read it back, showing the
wrong set and count of games.

Treat any narrowing parameter as scoped so those sets compute live.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/endpoints/roms/__init__.py

@@ -573,13 +573,37 @@ def get_roms(
         include_file_stats=True,
     )
 
-    # Cache only the unscoped library scan; scoped/searched sets are narrower and computed live.
+    # Cache only the fully unscoped library scan; any narrowing parameter makes
+    # the result set narrower, so it is computed live. The sidecar cache key
+    # encodes only user/order/grouping, not the filters, so every filter applied
+    # to `query` below must gate caching here or a narrowed list leaks under the
+    # shared "all" key. Bool flags use `is not None` since False is an active
+    # filter. Logic operators are omitted: they only matter when their list
+    # filter is set, which is already covered.
     is_unscoped = not (
         search_term
         or platform_ids
         or collection_id
         or virtual_collection_id
         or smart_collection_id
+        or genres
+        or franchises
+        or collections
+        or companies
+        or age_ratings
+        or statuses
+        or regions
+        or languages
+        or player_counts
+        or updated_after
+        or matched is not None
+        or favorite is not None
+        or duplicate is not None
+        or last_played is not None
+        or playable is not None
+        or has_ra is not None
+        or missing is not None
+        or verified is not None
     )
 
     # Get the char index for the roms

backend/tools/generate_test_data.py

@@ -714,11 +714,6 @@ def main() -> int:
     parser.add_argument(
         "--password", default="password", help="Plain password for every seeded user"
     )
-    parser.add_argument(
-        "--user-prefix",
-        default="loadtest",
-        help="Prefix for seeded usernames (kept unique by id)",
-    )
     parser.add_argument(
         "--wipe",
         action="store_true",
@@ -852,11 +847,11 @@ def main() -> int:
         # Suffix with the assigned id so usernames/emails never collide with
         # rows already in the target database.
         if i == 0:
-            username, role = f"{args.user_prefix}_admin_{uid}", Role.ADMIN
+            username, role = f"admin_{uid}", Role.ADMIN
         elif i <= 2:
-            username, role = f"{args.user_prefix}_editor_{uid}", Role.EDITOR
+            username, role = f"editor_{uid}", Role.EDITOR
         else:
-            username, role = f"{args.user_prefix}_viewer_{uid}", Role.VIEWER
+            username, role = f"viewer_{uid}", Role.VIEWER
         created = rand_past(rng, now)
         user_rows.append(
             {