fix: Update Survey Image label color for dark mode

- Add text-foreground and dark:text-gray-300 classes to Survey Image label
- Match styling with other form labels for consistency
- Improve readability in dark mode (similar to Google Forms)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: Zeff01

apps/codebility/app/home/settings/surveys/_components/SurveyImageUpload.tsx

@@ -108,7 +108,7 @@ export default function SurveyImageUpload({
 
   return (
     <div className="space-y-3">
-      <Label className="text-sm font-medium">Survey Image (Optional)</Label>
+      <Label className="text-sm font-medium text-foreground dark:text-gray-300">Survey Image (Optional)</Label>
 
       <div className="flex flex-col gap-3">
         {/* Image Preview */}