feat(client,setting): complete Phase 2 with partitioned client_follow_logs

- apps/client (11 models): Client, ClientContact, ClientRequirement,
  ClientSchoolPreference, ClientFollowLog (partitioned),
  ClientFollowLogAttachment, ClientViewing, ClientPropertyMatch,
  ClientStatusLog, ClientFavoriteFolder, ClientFolderItem
- apps/client/0002 RunSQL: PARTITION BY RANGE(created_at) for
  client_follow_logs + monthly partitions + default; triggers
  update_client_last_follow + update_client_viewing_progress;
  partial unique index on client_no WHERE deleted_at IS NULL
- apps/setting (4 models): LookupGroup, LookupItem, TenantSetting,
  FieldRequirementRule (tenant schema only per spec)

manage.py check green; all 9 Phase 2 apps complete.

apps/setting/models/__init__.py

@@ -0,0 +1,9 @@
+from .lookup import LookupGroup, LookupItem
+from .setting import FieldRequirementRule, TenantSetting
+
+__all__ = [
+    "LookupGroup",
+    "LookupItem",
+    "TenantSetting",
+    "FieldRequirementRule",
+]