fix: /files total count from DB (was hardcoded 0)

src/api/identity_api.rs

@@ -98,9 +98,11 @@ async fn list_files(
         })
         .collect();
 
+    let total = state.db.count_files().await.map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
+
     Ok(Json(FilesResponse {
         success: true,
-        total: 0, // TODO: Implement count query
+        total,
         page,
         page_size,
         data,

src/core/db/postgres_db.rs

@@ -2374,6 +2374,13 @@ impl PostgresDb {
         Ok(rows)
     }
 
+    pub async fn count_files(&self) -> Result<i64> {
+        let count: (i64,) = sqlx::query_as("SELECT COUNT(*) FROM videos")
+            .fetch_one(&self.pool)
+            .await?;
+        Ok(count.0)
+    }
+
     pub async fn get_file_by_uuid(&self, uuid: &str) -> Result<Option<FileRecord>> {
         let query = r#"
             SELECT file_uuid, file_path, file_name, status, probe_json, created_at