Fix: Cancel button functionality and live updates in booking management

- Add confirmation modal for booking cancellations
- Implement proper error handling and success messages
- Fix live updates for booking status changes
- Add manual refetch to ensure immediate UI updates
- Auto-delete past availability slots on list access
- Add manual cleanup function for past slots
- Improve user experience with instant feedback

src/client/components/admin-availability.tsx

@@ -42,6 +42,9 @@ export function AdminAvailability() {
   const { mutate: removeSlot } = useMutation(
     queryClient.availability.remove.mutationOptions()
   );
+  const { mutate: cleanupPastSlots } = useMutation(
+    queryClient.availability.cleanupPastSlots.mutationOptions()
+  );
 
   // Auto-update duration when treatment is selected
   useEffect(() => {
@@ -280,6 +283,41 @@ export function AdminAvailability() {
         </div>
       </div>
 
+      {/* Cleanup Button */}
+      <div className="bg-white rounded-lg shadow p-4">
+        <div className="flex items-center justify-between">
+          <div>
+            <h3 className="text-lg font-medium text-gray-900">Bereinigung</h3>
+            <p className="text-sm text-gray-600">Vergangene Slots automatisch löschen</p>
+          </div>
+          <button
+            onClick={() => {
+              const sessionId = localStorage.getItem("sessionId") || "";
+              if (!sessionId) {
+                setErrorMsg("Nicht eingeloggt. Bitte als Inhaber anmelden.");
+                return;
+              }
+              
+              cleanupPastSlots(
+                { sessionId },
+                {
+                  onSuccess: (result: any) => {
+                    setSuccessMsg(result.message || "Bereinigung abgeschlossen.");
+                    refetchSlots();
+                  },
+                  onError: (err: any) => {
+                    setErrorMsg(err?.message || "Fehler bei der Bereinigung.");
+                  }
+                }
+              );
+            }}
+            className="px-4 py-2 bg-orange-600 text-white rounded-md hover:bg-orange-700 transition-colors"
+          >
+            Vergangene Slots löschen
+          </button>
+        </div>
+      </div>
+
       {/* All Slots List */}
       <div className="bg-white rounded-lg shadow">
         <div className="p-4 border-b">