fix: defer daily report push и увеличить pool БД (0.4.12)

FCM/каналы для report.daily.* после commit ingest (BackgroundTasks);
SAC_DB_POOL_SIZE=15, SAC_DB_MAX_OVERFLOW=25 для штурма 09:00.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/config.py

@@ -34,6 +34,8 @@ class Settings(BaseSettings):
     model_config = _settings_config()
 
     database_url: str = "postgresql+psycopg2://sac:sac@localhost:5432/sac"
+    sac_db_pool_size: int = 15
+    sac_db_max_overflow: int = 25
     sac_public_url: str = "http://localhost:8000"
     jwt_secret: str = "change-me-in-production"
     jwt_algorithm: str = "HS256"