Implement anonymous account mode (Issue #2)

- Modified index route to allow browsing without login
- Set default user_settings for anonymous users with safe defaults
- Added anonymous flag to dashboard template
- Updated navigation to show Login/Sign Up buttons for anonymous users
- Changed feed header to "Public Feed" for anonymous browsing
- Hide Customize button for anonymous users

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

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

app.py

@@ -276,8 +276,18 @@ def index():
 
         return render_template('dashboard.html', user_settings=user_settings)
     else:
-        # Redirect non-authenticated users to login
-        return redirect(url_for('login'))
+        # Anonymous mode - allow browsing with default settings
+        user_settings = {
+            'filter_set': 'no_filter',
+            'communities': [],
+            'experience': {
+                'infinite_scroll': False,
+                'auto_refresh': False,
+                'push_notifications': False,
+                'dark_patterns_opt_in': False
+            }
+        }
+        return render_template('dashboard.html', user_settings=user_settings, anonymous=True)
 
 
 @app.route('/feed/<filterset>')