Optimize Media Matching Workflow

- **Preload Thumbnails**: Implemented image preloading in the media matching wizard to ensure instant rendering of candidate matches.
- **Async Linking**: Refactored the linking confirmation to be asynchronous. The UI now optimistically advances to the next match immediately, performing the backend linking in the background.
- **Completion Gate**: Added a check to ensure all pending background linking operations verify completion before the wizard closes and reloading occurs.
- **Video Support**: Verified that filename-based matching correctly handles video files by extracting filenames from Shopify video URLs.

src/MediaManager.html

@@ -1678,6 +1678,13 @@
           this.matches = newMatches;
           this.currentMatchIndex = 0;
           ui.logStatus('info', 'Found ' + newMatches.length + ' potential matches. Starting matching wizard...', 'info');
+
+          // Preload Images
+          newMatches.forEach(function (m) {
+            if (m.drive && m.drive.thumbnail) new Image().src = m.drive.thumbnail;
+            if (m.shopify && m.shopify.thumbnail) new Image().src = m.shopify.thumbnail;
+          });
+
           this.startMatching();
         } else {
           // No matches, show UI
@@ -1740,35 +1747,36 @@
         }, 50);
       },
 
+      pendingLinks: 0,
+
       confirmLink() {
         var match = this.matches[this.currentMatchIndex];
         var _this = this;
 
-        document.getElementById('btn-match-confirm').disabled = true;
+        // Async Fire & Forget (from UI perspective)
-        document.getElementById('btn-match-confirm').innerText = "Linking...";
+        this.pendingLinks++;
-        document.getElementById('btn-match-skip').disabled = true;
-
         ui.logStatus('link', 'Linking ' + match.drive.filename + '...', 'info');
 
         google.script.run
           .withSuccessHandler(function () {
             ui.logStatus('link', 'Linked ' + match.drive.filename, 'success');
-            _this.nextMatch();
+            _this.pendingLinks--;
+            _this.checkMatchingDone();
           })
           .withFailureHandler(function (e) {
-            alert("Failed to link: " + e.message);
+            ui.logStatus('link', 'Failed to link ' + match.drive.filename + ': ' + e.message, 'error');
-            document.getElementById('btn-match-confirm').disabled = false;
+            _this.pendingLinks--;
-            document.getElementById('btn-match-confirm').innerText = "Yes, Link";
+            _this.checkMatchingDone();
-            document.getElementById('btn-match-skip').disabled = false;
           })
           .linkDriveFileToShopifyMedia(state.sku, match.drive.id, match.shopify.id);
+
+        // Move to next immediately
+        this.nextMatch();
       },
 
       skipLink() {
-        document.getElementById('btn-match-skip').innerText = "Skipping...";
+        // No async op needed for skip
-        document.getElementById('btn-match-skip').disabled = true;
+        this.nextMatch();
-        document.getElementById('btn-match-confirm').disabled = true;
-        setTimeout(() => this.nextMatch(), 200);
       },
 
       nextMatch() {
@@ -1776,13 +1784,38 @@
         if (this.currentMatchIndex < this.matches.length) {
           this.renderMatch();
         } else {
-          // Done
+          this.checkMatchingDone();
+        }
+      },
+
+      checkMatchingDone() {
+        // 1. Are we visually done?
+        if (this.currentMatchIndex < this.matches.length) return;
+
+        // 2. Are background jobs done?
+        if (this.pendingLinks > 0) {
+          // Show "Waiting" state in Modal
+          document.getElementById('matching-modal').style.display = 'flex'; // Ensure open
+          document.getElementById('btn-match-confirm').disabled = true;
+          document.getElementById('btn-match-skip').disabled = true;
+
+          // Re-purpose the modal content temporarily or overlay?
+          // Let's just update the title/status
+          var title = document.querySelector('#matching-modal h3');
+          if (title) title.innerText = "Finalizing...";
+
+          var p = document.querySelector('#matching-modal p');
+          if (p) p.innerText = "Finishing " + this.pendingLinks + " pending link operations...";
+
+          return;
+        }
+
+        // All Done
         document.getElementById('matching-modal').style.display = 'none';
         ui.logStatus('info', 'Matching complete. Reloading...', 'info');
         document.getElementById('loading-ui').style.display = 'block';
         // Reload to get fresh state. Since hasRunMatching is true, it shouldn't trigger again.
         this.loadMedia(true);
-        }
       },
 
       // Sand Animation (Global Loop)