feat: fix analytics dashboard and implement complete Umami integration

- Fix backend analytics to include both 'download' and 'download_all' actions
- Add Analytics tab to Settings page for Umami configuration
- Update public settings endpoint to expose Umami config when enabled
- Implement dynamic Umami initialization from backend settings
- Fix frontend analytics calculations (remove hardcoded estimations)
- Add proper download counts and unique visitor tracking
- Update CLAUDE.md with production safety guidelines

The analytics dashboard now shows accurate data for all metrics, and Umami
can be configured through the admin panel instead of environment variables.

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

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

backend/src/routes/publicSettings.js

@@ -5,9 +5,9 @@ const router = express.Router();
 // Get public settings (branding and theme)
 router.get('/', async (req, res) => {
   try {
-    // Fetch branding, theme, general, and select security settings
+    // Fetch branding, theme, general, security, and analytics settings
     const settings = await db('app_settings')
-      .whereIn('setting_type', ['branding', 'theme', 'general', 'security'])
+      .whereIn('setting_type', ['branding', 'theme', 'general', 'security', 'analytics'])
       .select('setting_key', 'setting_value');
     
     // Convert to object format
@@ -41,7 +41,12 @@ router.get('/', async (req, res) => {
       enable_analytics: settingsObject.general_enable_analytics !== false,
       enable_recaptcha: settingsObject.security_enable_recaptcha === true || settingsObject.security_enable_recaptcha === 'true',
       recaptcha_site_key: settingsObject.security_recaptcha_site_key || null,
-      maintenance_mode: settingsObject.general_maintenance_mode === true || settingsObject.general_maintenance_mode === 'true'
+      maintenance_mode: settingsObject.general_maintenance_mode === true || settingsObject.general_maintenance_mode === 'true',
+      // Umami analytics configuration (only if enabled)
+      umami_enabled: settingsObject.analytics_umami_enabled === true || settingsObject.analytics_umami_enabled === 'true',
+      umami_url: settingsObject.analytics_umami_enabled ? (settingsObject.analytics_umami_url || null) : null,
+      umami_website_id: settingsObject.analytics_umami_enabled ? (settingsObject.analytics_umami_website_id || null) : null,
+      umami_share_url: settingsObject.analytics_umami_enabled ? (settingsObject.analytics_umami_share_url || null) : null
     };
 
     res.json(publicSettings);