Multiple changes

- Excel from network folder
- multiple input Excel via dowpdown,
- free creation date,
- Output folder path tooltip

src/config_loader.py

@@ -66,6 +66,10 @@ def load_config(config_path: Path | None = None) -> Dict[str, Any]:
 
     # Optional settings with backward-compatible defaults
     data.setdefault("pdf_need_appearances", False)
+    data.setdefault(
+        "excel_network_source",
+        r"J:\Fachbereiche\BO\Produktionsschule\Maßnahmeunterlagen\30_Teilnehmende\01_Anwesenheit\Anwesenheitsliste\Anwesenheitsliste 2026.xlsx",
+    )
 
     _config_cache = data
     _config_path_cache = config_path