refactor: simplify database logging handler

- Remove retry logic from DatabaseLogHandler (was for SQLite locking)
- Streamline error handling in log emission
- Clean up platform health service

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/services/platform_health_service.py

@@ -305,27 +305,13 @@ class PlatformHealthService:
     def _get_database_size(self, db: Session) -> float:
         """Get database size in MB."""
         try:
-            # Try SQLite approach
-            result = db.execute(
-                text(
-                    "SELECT page_count * page_size as size "
-                    "FROM pragma_page_count(), pragma_page_size()"
-                )
-            )
-            row = result.fetchone()
-            if row:
-                return round(row[0] / (1024 * 1024), 2)
-        except Exception:
-            pass
-
-        try:
-            # Try PostgreSQL approach
             result = db.execute(text("SELECT pg_database_size(current_database())"))
             row = result.fetchone()
             if row:
                 return round(row[0] / (1024 * 1024), 2)
         except Exception:
-            pass
+            logger.warning("Failed to get database size")
+            return 0.0
 
         return 0.0