feat: add provider analytics summary

backend/app/api/stories.py

@@ -19,6 +19,7 @@ from app.schemas.story_schemas import (
     GenerateRequest,
     GenerationJobDetailResponse,
     GenerationJobSummaryResponse,
+    GenerationProviderAnalyticsResponse,
     GenerationProviderStatsResponse,
     GenerationRequest,
     GenerationResponse,
@@ -34,6 +35,7 @@ from app.services import story_service
 from app.services.generation_jobs import (
     get_generation_job_detail,
     get_story_provider_stats,
+    get_user_provider_analytics,
     list_story_generation_jobs,
 )
 from app.services.memory_service import build_enhanced_memory_context
@@ -83,6 +85,18 @@ async def get_generation_job(
     return await get_generation_job_detail(db, job_id=job_id, user_id=user.id)
 
 
+@router.get(
+    "/generations/provider-analytics",
+    response_model=GenerationProviderAnalyticsResponse,
+)
+async def get_generation_provider_analytics(
+    user: User = Depends(require_user),
+    db: AsyncSession = Depends(get_db),
+):
+    """Get provider call stats aggregated across the user's generation history."""
+    return await get_user_provider_analytics(db, user_id=user.id)
+
+
 @router.get(
     "/generations/{story_id}/jobs",
     response_model=list[GenerationJobSummaryResponse],