Fix platform_settings table name and RLS policy

- Update migration to use correct table name (platform_settings, not site_settings)
- Fix WebinarRecording.tsx to query platform_settings table
- Fix Bootcamp.tsx to query platform_settings table
- This allows authenticated users to access brand_accent_color for theming

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/pages/WebinarRecording.tsx

@@ -68,7 +68,7 @@ export default function WebinarRecording() {
 
     // Fetch accent color from settings
     const { data: settings } = await supabase
-      .from('site_settings')
+      .from('platform_settings')
       .select('brand_accent_color')
       .single();