Add Facebook Writer API with models, routers, and migration summary

Co-authored-by: ajay.calsoft <ajay.calsoft@gmail.com>

backend/api/facebook_writer/services/__init__.py

@@ -0,0 +1,29 @@
+"""Facebook Writer Services."""
+
+from .base_service import FacebookWriterBaseService
+from .post_service import FacebookPostService
+from .story_service import FacebookStoryService
+from .ad_copy_service import FacebookAdCopyService
+from .remaining_services import (
+    FacebookReelService,
+    FacebookCarouselService,
+    FacebookEventService,
+    FacebookHashtagService,
+    FacebookEngagementService,
+    FacebookGroupPostService,
+    FacebookPageAboutService
+)
+
+__all__ = [
+    "FacebookWriterBaseService",
+    "FacebookPostService",
+    "FacebookStoryService", 
+    "FacebookReelService",
+    "FacebookCarouselService",
+    "FacebookEventService",
+    "FacebookHashtagService",
+    "FacebookEngagementService",
+    "FacebookGroupPostService",
+    "FacebookPageAboutService",
+    "FacebookAdCopyService"
+]