fix(fetch): add proxy fallbacks and improved error logging for dropbox

src/App.tsx

@@ -24,19 +24,36 @@ export default function App() {
 
   useEffect(() => {
     const loadDefaultData = async () => {
-      try {
+      // Use different proxies as fallbacks
+      const proxies = [
+        (url: string) => `https://api.allorigins.win/raw?url=${encodeURIComponent(url)}`,
+        (url: string) => `https://cors-anywhere.herokuapp.com/${url}`, // Often needs manual activation but we'll try
+        (url: string) => `https://thingproxy.freeboard.io/fetch/${url}`
+      ];
+
+      const dropboxUrl = 'https://dl.dropboxusercontent.com/scl/fi/nkyabkq2jdwfudof2ovrl/Data-Matrix.xlsx?rlkey=1cz5fuabwipqqivihii7sybw0&st=io0g4wvb&dl=1';
+      
       setIsLoadingDefault(true);
       setDefaultLoadError(null);
-        // Using allorigins proxy to avoid Dropbox CORS issues and improve reliability
-        const dropboxUrl = 'https://dl.dropboxusercontent.com/scl/fi/nkyabkq2jdwfudof2ovrl/Data-Matrix.xlsx?rlkey=1cz5fuabwipqqivihii7sybw0&st=io0g4wvb&dl=1';
-        const proxyUrl = `https://api.allorigins.win/raw?url=${encodeURIComponent(dropboxUrl)}`;
+
+      let lastError = null;
+
+      for (const getProxyUrl of proxies) {
+        try {
+          const proxyUrl = getProxyUrl(dropboxUrl);
+          console.log(`Attempting to fetch via: ${proxyUrl}`);
           
           const response = await fetch(proxyUrl);
+          
           if (!response.ok) {
-          throw new Error(`Failed to fetch file: ${response.statusText}`);
+            throw new Error(`Proxy returned status ${response.status}: ${response.statusText}`);
           }
           
           const arrayBuffer = await response.arrayBuffer();
+          if (arrayBuffer.byteLength < 100) {
+              throw new Error("File too small, possibly empty or error page");
+          }
+
           const wb = XLSX.read(arrayBuffer, { type: 'array' });
           const wsname = wb.SheetNames[0];
           const ws = wb.Sheets[wsname];
@@ -46,18 +63,23 @@ export default function App() {
             setAppState({
               headers: data[0],
               data: data.slice(1),
-            fileName: 'Data-Matrix.xlsx (Auto-loaded Google Drive/Dropbox)',
+              fileName: 'Data-Matrix.xlsx (Cloud Sync)',
               fileDate: new Date(),
               hasUnsavedChanges: false
             });
             setActiveModule('descriptions');
+            setIsLoadingDefault(false);
+            return; // Success!
           }
         } catch (err) {
-        console.error('Error loading default data:', err);
-        setDefaultLoadError(err instanceof Error ? err.message : 'Unknown error');
-      } finally {
-        setIsLoadingDefault(false);
+          console.error(`Failed with proxy:`, err);
+          lastError = err;
         }
+      }
+
+      // If we reach here, all proxies failed
+      setDefaultLoadError(lastError instanceof Error ? lastError.message : 'All connection attempts failed');
+      setIsLoadingDefault(false);
     };
 
     loadDefaultData();