fix: clear thumbnail cache and temp dirs on new session

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

src-tauri/src/commands/media_analysis.rs

@@ -35,3 +35,10 @@ pub async fn extract_thumbnails(
     .await
     .map_err(|e| format!("Task failed: {e}"))?
 }
+
+#[tauri::command]
+pub async fn cleanup_thumbnails(paths: Vec<String>) -> Result<(), String> {
+    tokio::task::spawn_blocking(move || thumbnail_extractor::cleanup_thumbnail_dirs(&paths))
+        .await
+        .map_err(|e| format!("Task failed: {e}"))?
+}