feat: update Dropbox source URL and implement smart dirty-checking for row highlight

src/App.tsx

@@ -318,23 +318,48 @@ export default function App() {
 
   const handleSaveRow = (rowIndex: number, updatedRow: ExcelRow) => {
     const articleNo = String(updatedRow[COLUMNS.ARTICLE_NO]);
-    const originalData = appState.data[rowIndex]; // Capture before update
+    const currentPending = pendingRows[articleNo];
+    const originalData = currentPending?.originalData ?? appState.data[rowIndex];
+
+    // Check if the new state is actually different from the original (not the current)
+    const isActuallyModified = JSON.stringify(updatedRow) !== JSON.stringify(originalData);
+
     setAppState(prev => {
       const newData = [...prev.data];
       newData[rowIndex] = updatedRow;
       return { ...prev, data: newData, hasUnsavedChanges: true };
     });
-    setPendingRows(prev => ({
-      ...prev,
-      [articleNo]: {
-        rowIndex,
-        // Keep the very first originalData if already pending (re-edit case)
-        originalData: prev[articleNo]?.originalData ?? originalData,
-        newData: updatedRow,
-        articleName: String(updatedRow[COLUMNS.ARTICLE_NAME] || articleNo),
-      }
-    }));
-    setRowStatuses(prev => ({ ...prev, [articleNo]: 'pending' }));
+
+    if (isActuallyModified) {
+      setPendingRows(prev => {
+        const next = {
+          ...prev,
+          [articleNo]: {
+            rowIndex,
+            originalData,
+            newData: updatedRow,
+            articleName: String(updatedRow[COLUMNS.ARTICLE_NAME] || articleNo),
+          }
+        };
+        setAppState(app => ({ ...app, hasUnsavedChanges: true }));
+        return next;
+      });
+      setRowStatuses(prev => ({ ...prev, [articleNo]: 'pending' }));
+    } else {
+      // It was changed back to its original state - remove from pending
+      setPendingRows(prev => {
+        const n = { ...prev };
+        delete n[articleNo];
+        const stillHasChanges = Object.keys(n).length > 0;
+        setAppState(app => ({ ...app, hasUnsavedChanges: stillHasChanges }));
+        return n;
+      });
+      setRowStatuses(prev => {
+        const n = { ...prev };
+        delete n[articleNo];
+        return n;
+      });
+    }
     setEditingRowIndex(null);
   };