Optimize Media Manager sheet update trigger

- Update mediaHandlers.ts to accept an optional forcedThumbnailUrl in updateSpreadsheetThumbnail, enabling updates without re-fetching backend state.

- Update MediaManager.html execution plan to trigger the sheet update immediately (optimistically) using the predicted first item from the plan, running in parallel with other execution phases.

- Ensure the execution flow waits for both the sheet update and other operations to complete before finishing.

src/MediaManager.html

@@ -1975,10 +1975,48 @@
           }
         };
 
+        // Optimistic Sheet Update (Immediate Parallel Execution)
+        const pSheet = new Promise(resolve => {
+          const first = activeItems[0];
+          let url = null;
+          if (first) {
+            // Determine best URL based on item type
+            // Note: MediaHandlers logic prioritizes Shopify URL if present.
+            // We mimic that logic here.
+            const isShopify = (first.source === 'shopify_only' || first.source === 'synced') && first.thumbnail;
+
+            if (isShopify) {
+              url = first.thumbnail;
+            } else if (first.id) {
+              // Drive Item - Construct URL compatible with server logic
+              url = "https://drive.google.com/thumbnail?id=" + first.id + "&sz=w400";
+            }
+          }
+
+          if (!url) {
+            updateStatus('prog-sheet', 'Skipped', '#aaa');
+            resolve();
+            return;
+          }
+
+          updateStatus('prog-sheet', 'Running...', 'blue');
+          google.script.run
+            .withSuccessHandler(() => {
+              updateStatus('prog-sheet', 'Done', 'green');
+              resolve();
+            })
+            .withFailureHandler(e => {
+              console.warn("Sheet update failed", e);
+              updateStatus('prog-sheet', 'Failed (Warn)', 'orange');
+              resolve(); // Don't block completion
+            })
+            .updateSpreadsheetThumbnail(state.sku, url);
+        });
+
         // Phase 1: Deletions
         if (plan.deletions.length === 0) {
           updateStatus('prog-delete', 'Skipped', '#aaa');
-          this.startParallelPhases(plan, activeItems, jobId);
+          this.startParallelPhases(plan, activeItems, jobId, pSheet);
           return;
         }
 
@@ -1987,7 +2025,7 @@
         google.script.run
           .withSuccessHandler(() => {
             updateStatus('prog-delete', 'Done', 'green');
-            this.startParallelPhases(plan, activeItems, jobId);
+            this.startParallelPhases(plan, activeItems, jobId, pSheet);
           })
           .withFailureHandler(e => {
             updateStatus('prog-delete', 'Failed', 'red');
@@ -1998,7 +2036,7 @@
           .executeSavePhase(state.sku, 'deletions', plan.deletions, jobId);
       },
 
-      startParallelPhases(plan, activeItems, jobId) {
+      startParallelPhases(plan, activeItems, jobId, pSheet) {
         // Helper function defined at the top to avoid hoisting issues
         const updateStatus = (id, status, color) => {
           const el = document.getElementById(id);
@@ -2009,7 +2047,6 @@
         };
 
         // Phase 2 & 3: Adoptions & Uploads (Parallel)
-
         const pAdoption = new Promise((resolve, reject) => {
           if (plan.adoptions.length === 0) {
             updateStatus('prog-adopt', 'Skipped', '#aaa');
@@ -2043,34 +2080,36 @@
         Promise.all([pAdoption, pUpload])
           .then(() => {
             // Phase 4: Reorder
-            if (plan.reorders.length === 0 && plan.deletions.length === 0 && plan.adoptions.length === 0 && plan.uploads.length === 0) {
+            const pReorder = new Promise((resolve, reject) => {
-              // Nothing to reorder usually means no changes, but if we just changed metadata?
-              // Reorder always runs to ensure "0001" suffixes are correct if we deleted something.
-              // But if plan.reorders is empty, likely no items left.
               if (plan.reorders.length === 0) {
                 updateStatus('prog-reorder', 'Skipped', '#aaa');
-                updateStatus('prog-sheet', 'Running...', 'blue');
+                 resolve();
-                // Still update sheet? Yes.
+                 return;
-              }
                }
 
-            if (plan.reorders.length > 0) {
                updateStatus('prog-reorder', 'Running...', 'blue');
                google.script.run
                  .withSuccessHandler(() => {
                    updateStatus('prog-reorder', 'Done', 'green');
-                  updateStatus('prog-sheet', 'Running...', 'blue');
+                   resolve();
-                  this.runSheetUpdate();
                  })
                  .withFailureHandler(e => {
                    alert("Reorder Phase Failed: " + e.message);
-                  this.finishSave(false);
+                   reject(e);
                  })
                  .executeSavePhase(state.sku, 'reorder', plan.reorders, jobId);
-            } else {
+             });
-              updateStatus('prog-sheet', 'Running...', 'blue');
+
-              this.runSheetUpdate();
+            // Wait for BOTH Reorder and Early Sheet Update
-            }
+            Promise.all([pReorder, pSheet])
+              .then(() => {
+                this.finishSave(true);
+              })
+              .catch(e => {
+                // If reorder failed, we already alerted.
+                console.error("Save completion failed", e);
+                this.finishSave(false);
+              });
           })
           .catch(e => {
             alert("Parallel Execution Failed: " + e.message);
@@ -2079,22 +2118,6 @@
           });
       },
 
-      runSheetUpdate() {
-        google.script.run
-          .withSuccessHandler(() => {
-            const el = document.getElementById('prog-sheet');
-            if (el) { el.style.color = 'green'; el.innerText = el.innerText.split(':')[0] + ': Done'; }
-            this.finishSave(true);
-          })
-          .withFailureHandler(e => {
-            console.error("Sheet update failed", e);
-            const el = document.getElementById('prog-sheet');
-            if (el) { el.style.color = 'orange'; el.innerText = el.innerText.split(':')[0] + ': Done (Sheet Warn)'; }
-            this.finishSave(true);
-          })
-          .updateSpreadsheetThumbnail(state.sku);
-      },
-
       finishSave(success) {
             this.stopLogPolling();
         if (success) {

src/mediaHandlers.ts

@@ -119,7 +119,7 @@ export function saveMediaChanges(sku: string, finalState: any[], jobId: string |
   return logs
 }
 
-export function updateSpreadsheetThumbnail(sku: string) {
+export function updateSpreadsheetThumbnail(sku: string, forcedThumbnailUrl: string | null = null) {
   const config = new Config()
   const driveService = new GASDriveService()
   const shop = new Shop()
@@ -128,6 +128,31 @@ export function updateSpreadsheetThumbnail(sku: string) {
   const mediaService = new MediaService(driveService, shopifyMediaService, networkService, config)
 
   const ss = new GASSpreadsheetService();
+
+  // Optimization: If forced URL provided (optimistic update), skip state calculation
+  if (forcedThumbnailUrl) {
+      try {
+          const row = ss.getRowNumberByColumnValue("product_inventory", "sku", sku);
+          if (row) {
+              const thumbUrl = forcedThumbnailUrl;
+              try {
+                  const image = SpreadsheetApp.newCellImage()
+                    .setSourceUrl(thumbUrl)
+                    .setAltTextTitle(sku)
+                    .setAltTextDescription(`Thumbnail for ${sku}`)
+                    .build();
+                  ss.setCellValueByColumnName("product_inventory", row, "thumbnail", image);
+              } catch (builderErr) {
+                  ss.setCellValueByColumnName("product_inventory", row, "thumbnail", `=IMAGE("${thumbUrl}")`);
+              }
+          }
+          return;
+      } catch (e) {
+          console.warn("Failed to update sheet thumbnail (forced)", e);
+          throw new Error("Sheet Update Failed: " + e.message);
+      }
+  }
+
   const product = new Product(sku);
 
   // Need Shopify ID for accurate state logic?