Fix Amplify environment variable access

- Simplified amplify.yml to export env var during build
- Updated both gallery and dadvocate pages to check multiple env var names
- Added debugging to show available env vars
- Added publicRuntimeConfig and serverRuntimeConfig to next.config.ts
- Created config helper in lib/config.ts

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

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

next.config.ts

@@ -24,6 +24,14 @@ const nextConfig: NextConfig = {
       },
     ],
   },
+  // Make environment variables available to the browser
+  publicRuntimeConfig: {
+    YOUTUBE_API_KEY: process.env.YOUTUBE_API_KEY,
+  },
+  // Server-side environment variables
+  serverRuntimeConfig: {
+    YOUTUBE_API_KEY: process.env.YOUTUBE_API_KEY,
+  },
 };
 
 export default nextConfig;