Remove registration page and redirect home to timeline

Remove the registration UI page completely and use the public timeline as the default start page.

Changes:
- Delete auth/register.html template
- Remove /register route from AuthViewController
- Update HomeController to redirect / to /timeline
- Remove /register from public paths list in auth.js

Users will no longer see a registration option in the UI. Registration can only be done via direct API calls if enabled.

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

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

src/main/resources/static/js/auth.js

@@ -267,7 +267,7 @@ const FitPubAuth = {
      */
     checkAuthStatus: function() {
         const currentPath = window.location.pathname;
-        const publicPaths = ['/', '/login', '/register', '/timeline'];
+        const publicPaths = ['/', '/login', '/timeline'];
 
         // Skip check for public paths
         if (publicPaths.includes(currentPath)) {