Fix Plyr controls and site_settings permissions

## Changes

### Video Player CSS Overlay Fix
- Moved overlay inside plyr__video-embed container
- Added check for plyr__control--overlaid (play button)
- Now only blocks YouTube iframe, not Plyr controls
- Preserves full functionality of play button, progress bar, etc.

### Site Settings Permissions
- Added RLS policy to make site_settings publicly readable
- All authenticated users can now access brand_accent_color
- Fixes 404 error when members try to fetch accent color

## Technical Details
- Overlay now properly allows clicks through to Plyr controls
- Site settings now accessible via public RLS policy for authenticated users

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

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

supabase/migrations/20251231000001_public_site_settings.sql

@@ -0,0 +1,10 @@
+-- Make site_settings publicly accessible for accent color
+-- All users (authenticated) can read brand settings
+
+DROP POLICY IF EXISTS "site_settings_public_select" ON site_settings;
+
+CREATE POLICY "site_settings_public_select"
+ON site_settings
+FOR SELECT
+TO authenticated
+USING (true);