feat: Add TTS statistics endpoint and service method for comprehensive TTS data

app/services/dashboard.py

@@ -85,6 +85,21 @@ class DashboardService:
             )
             raise
 
+    async def get_tts_statistics(self) -> dict[str, Any]:
+        """Get comprehensive TTS statistics."""
+        try:
+            stats = await self.sound_repository.get_soundboard_statistics("TTS")
+
+            return {
+                "sound_count": stats["count"],
+                "total_play_count": stats["total_plays"],
+                "total_duration": stats["total_duration"],
+                "total_size": stats["total_size"],
+            }
+        except Exception:
+            logger.exception("Failed to get TTS statistics")
+            raise
+
     def _get_date_filter(self, period: str) -> datetime | None:  # noqa: PLR0911
         """Calculate the date filter based on the period."""
         now = datetime.now(UTC)