feat(complex): add apps.complex with 10 models and full-text search

- 10 models: Complex, ComplexAlias, ComplexBusinessArea, ComplexSchool, ComplexMetroStation, Building, RoomUnit, ComplexPhoto, ComplexAttachment, ComplexPriceTrend
- RunSQL migration: pg_trgm extension, gin_trgm_ops indexes, tsvector triggers for complex search_vector (from name/alias/address)
- Optimistic locking via version field on Complex
- 4 lock flags (lock_building/room/info/standard_room) per spec
- Adds ComplexPropertyUsageType + ComplexBuildingStructure enums
- manage.py check passes

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

core/enums.py

@@ -352,6 +352,20 @@ class ComplexPhotoCategory(models.TextChoices):
     OTHER = "other", "其他"
 
 
+class ComplexPropertyUsageType(models.TextChoices):
+    RESIDENTIAL = "residential", "住宅"
+    VILLA = "villa", "别墅"
+    COMMERCIAL_RESIDENTIAL = "commercial_residential", "商住"
+    COMMERCIAL = "commercial", "商业"
+    OFFICE = "office", "写字楼"
+    OTHER = "other", "其他"
+
+
+class ComplexBuildingStructure(models.TextChoices):
+    UNIT_ROOM = "unit_room", "单元-房号"
+    OTHER = "other", "其他"
+
+
 # ──────────────────────────────────────────────────────────────
 # 3.5 property
 # ──────────────────────────────────────────────────────────────