feat(flags): added feature flags business and presentation logic

src/backend/apps/flags/selectors.py

@@ -0,0 +1,23 @@
+from django.db.models import QuerySet
+
+from apps.flags.models import FeatureFlag
+
+
+def feature_flag_list(
+    *,
+    value_type: str | None = None,
+    search: str | None = None,
+) -> QuerySet[FeatureFlag]:
+    qs = FeatureFlag.objects.all()
+
+    if value_type:
+        qs = qs.filter(value_type=value_type)
+
+    if search:
+        qs = qs.filter(key__icontains=search)
+
+    return qs
+
+
+def feature_flag_get_by_key(key: str) -> FeatureFlag | None:
+    return FeatureFlag.objects.filter(key=key).first()