fix: improve image quality setting and enhance error handling in image upload

mobile/src/pages/datacards.tsx

@@ -770,7 +770,7 @@ function ImageRotatorFields({ form, onChange, onUrlsChange }: ImageRotatorFields
     }
     const result = await ImagePicker.launchImageLibraryAsync({
       mediaTypes: "images",
-      quality: 0.8,
+      quality: 1,
       base64: true,
     });
     if (result.canceled) return;

mobile/src/pages/settings.tsx

@@ -49,7 +49,7 @@ export function SettingsPage() {
 
     const result = await ImagePicker.launchImageLibraryAsync({
       mediaTypes: "images",
-      quality: 0.85,
+      quality: 1,
       base64: true,
     });
 
@@ -63,16 +63,20 @@ export function SettingsPage() {
       return;
     }
 
+    if (!asset.base64) {
+      setStatus("Could not read image data. Please try again.");
+      return;
+    }
     const ext = (asset.mimeType?.split("/")[1] ?? asset.uri.split(".").pop() ?? "jpg").toLowerCase();
     setPendingUri(asset.uri);
-    setPendingBase64(asset.base64 ?? null);
+    setPendingBase64(asset.base64);
     setPendingExt(ext);
     setStatus(null);
   };
 
   // ── Upload pending image and save as background
   const handleSave = async () => {
-    if (!pendingBase64) return;
+    if (!pendingBase64) { setStatus("No image selected."); return; }
     setSaving(true);
     setStatus(null);
     try {