chore: Version auf 6.2.7 heben

Der Filter in delete_file verglich nur item["url"], traf damit aber nur
URL-Eintraege. Bei Dateien wurde die Datei vom Datentraeger geloescht,
der Eintrag {"name": ...} blieb als Karteileiche in der config.json
stehen - in der Priority-Playlist wie in jeder Screen-Playlist.
Vergleich laeuft jetzt ueber playlist_item_name(), das alle drei
Eintragsformen abdeckt.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

app.py

@@ -51,7 +51,7 @@ CONFIG_FILE = os.path.join(BASE_DIR, "config.json") # Persistente Konfiguration
 USERS_FILE = os.path.join(BASE_DIR, "users.json")   # User-Datenbank
 HISTORY_FILE = os.path.join(BASE_DIR, "history.json") # Aktivitätsverlauf
 
-APP_VERSION = "6.2.6"
+APP_VERSION = "6.2.7"
 UPLOAD_EXTENSIONS = {".jpg", ".jpeg", ".png", ".mp4"}
 
 app = Flask(__name__)
@@ -1878,18 +1878,15 @@ def delete_file(site, screen, filename):
     if screen == "priority":
         path = os.path.join(priority_dir(site), filename)
         playlist = get_priority_config(cfg, site).get("playlist", [])
-        playlist[:] = [item for item in playlist if not (
-            (isinstance(item, str) and item == filename) or
-            (isinstance(item, dict) and item.get("url") == filename)
-        )]
     else:
         path = os.path.join(MEDIA_DIR, site, screen, filename)
         screens_cfg = cfg.get("sites", {}).get(site, {}).get("screens", {})
         playlist = screens_cfg.get(screen, {}).get("playlist", [])
-        playlist[:] = [item for item in playlist if not (
-            (isinstance(item, str) and item == filename) or
-            (isinstance(item, dict) and item.get("url") == filename)
-        )]
+
+    # Ueber playlist_item_name vergleichen: Datei-Eintraege stehen als
+    # {"name": ...}, URLs als {"url": ...}, Altbestand als reiner String.
+    playlist[:] = [item for item in playlist
+                   if playlist_item_name(item) != filename]
 
     if os.path.exists(path):
         os.remove(path)