fix: cleanup only old uploads, restore fav state on tinder undo

- #11: cleanup_old_uploads() skips dirs younger than 24h (safe during --reload)
- #12: tinderHistory stores wasFav snapshot; undo restores exact pre-swipe favorite state

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server.py

@@ -31,13 +31,18 @@ load_dotenv()
 
 
 def cleanup_old_uploads():
-    """Löscht beim Start alle alten onlyframes-tmp-Ordner."""
+    """Löscht onlyframes-tmp-Ordner die älter als 24h sind."""
     tmp = tempfile.gettempdir()
+    cutoff = time() - 24 * 3600
     for name in os.listdir(tmp):
         if name.startswith("onlyframes-") and name != "onlyframes-server.log":
             path = os.path.join(tmp, name)
             if os.path.isdir(path):
-                shutil.rmtree(path, ignore_errors=True)
+                try:
+                    if os.path.getmtime(path) < cutoff:
+                        shutil.rmtree(path, ignore_errors=True)
+                except OSError:
+                    pass
 
 
 cleanup_old_uploads()