Fix OAuth authentication error on initial page load (#213)

Modified GitHub middleware to only apply authentication to API routes.
This allows users to access the login page without encountering
"GitHub token is required" errors.

- Skip authentication for non-API routes (/, /auth/*, static assets)
- Preserve authentication requirements for all /api/* endpoints
- Enable proper OAuth flow for new users

Resolves the catch-22 where users couldn't authenticate because
they couldn't access the authentication page.

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

Co-authored-by: Claude <[email protected]>

Author: karts

server/middleware/github.ts

@@ -3,6 +3,14 @@ import { authenticateAndGetGitHubHeaders } from '../modules/authentication';
 type Scope = 'org' | 'team' | 'ent';
 
 export default defineEventHandler(async (event) => {
+    // Only apply authentication to API routes
+    const url = event.node.req.url || '';
+    
+    // Skip authentication for non-API routes
+    if (!url.startsWith('/api/')) {
+        return;
+    }
+    
     // get runtime config
     const config = useRuntimeConfig(event);