ux: replace skip page confirm dialog with non-intrusive toast

- Remove blocking confirm("Skip this page?") dialog
- Show brief "Skipping page..." toast instead
- Add small delay for toast visibility before proceeding
- Much better UX for quick page navigation

Co-Authored-By: Claude (claude-opus-4-5-thinking) <noreply@anthropic.com>

templates/cropv2.html

@@ -1300,8 +1300,12 @@
         }
 
         async function processPage() {
-            if (!boxes.length && !confirm("Skip this page?")) return;
-            
+            if (!boxes.length) {
+                // Show non-intrusive toast and continue
+                toast('Skipping page...');
+                await new Promise(r => setTimeout(r, 300)); // Brief delay for toast visibility
+            }
+
             ProgressBar.show(0.3);
             document.getElementById('loader-overlay').style.display = 'flex';