Add button debouncing to prevent double API calls

- Disable button while request is in progress
- Re-enable button after request completes (success or error)
- Prevents React Strict Mode from firing duplicate simultaneous requests
- Fixes 'Body already consumed' error from parallel edge function calls

src/components/admin/settings/IntegrasiTab.tsx

@@ -380,6 +380,10 @@ export function IntegrasiTab() {
                 return;
               }
 
+              // Prevent multiple simultaneous clicks
+              const btn = document.activeElement as HTMLButtonElement;
+              if (btn) btn.disabled = true;
+
               try {
                 const { data, error } = await supabase.functions.invoke('create-google-meet-event', {
                   body: {
@@ -401,6 +405,8 @@ export function IntegrasiTab() {
                 }
               } catch (err: any) {
                 toast({ title: "Error", description: err.message, variant: "destructive" });
+              } finally {
+                if (btn) btn.disabled = false;
               }
             }}
             className="w-full border-2"