Clean up label-embedding architecture

- Move {id,label} stripping into _SetCriterion.from_json() so both
  MultiCriterion and ChoiceCriterion normalise at the parse boundary;
  the querying layer stays typed (list[int] / list[str]) and clean.
- Revert MultiCriterion to a thin _extra_q() override; _SetCriterion.to_q()
  is no longer duplicated.
- JS: readSearchSelect always emits {id, label} objects — no conditional
  mixed-type arrays. filter_bar.js stores them as-is for all fields,
  removing the fragile isIdField hardcoded list.
- Update tests to use the {id, label} filter format.

https://claude.ai/code/session_01EyAJcMoDktLrY9tSbdHViA

tests/test_filter_bars.py

@@ -94,7 +94,7 @@ class FilterBarRenderingTest(TestCase):
 
     def test_game_filter_bar_roundtrips_selected_status(self):
         """A status in filter_json renders as an include pill in the widget."""
-        filter_json = json.dumps({"status": {"value": ["f"], "modifier": ""}})
+        filter_json = json.dumps({"status": {"value": [{"id": "f", "label": "Finished"}], "modifier": "INCLUDES"}})
         html = str(
             FilterBar(
                 filter_json=filter_json, preset_list_url="/l", preset_save_url="/s"

tests/test_filters.py

@@ -121,6 +121,15 @@ class TestMultiCriterion:
         c = MultiCriterion(value=[], modifier=Modifier.IS_NULL)
         assert c.to_q("device_id") == Q(device_id__isnull=True)
 
+    def test_from_json_strips_embedded_labels(self):
+        """from_json normalises {id, label} dicts to bare ids."""
+        c = MultiCriterion.from_json(
+            {"value": [{"id": 797, "label": "Hollow Knight"}], "excludes": [{"id": 11, "label": "Steam Deck"}]}
+        )
+        assert c.value == [797]
+        assert c.excludes == [11]
+        assert c.to_q("game_id") == Q(game_id__in=[797]) & ~Q(game_id__in=[11])
+
 
 class TestChoiceCriterionAgainstDB:
     """Verify ChoiceCriterion produces correct DB results."""