fix: implement 9 production enhancements and security fixes

- Password Complexity: Added 4-level complexity selector (Simple/Moderate/Strong/Very Strong) in admin security settings with dynamic backend validation
- Gallery Security: Removed event date from login page (security risk), replaced with event type badge
- Analytics Config: Fixed "Not Configured" detection logic to check both admin settings and env variables
- Analytics Accuracy: Aligned calculation logic between dashboard and analytics endpoints, added totals verification
- Translations: Added missing activity keys (analytics_settings_updated, cms_page_updated, security_settings_updated, password_reset, admin_logout, system_activity)
- UI Fixes: Fixed German text overflow in CMS page selector with proper CSS truncation
- Date Format: Event creation now respects admin-configured date format instead of browser locale
- Chrome Compatibility: Replaced emoji flags with SVG components for Windows Chrome support

All changes maintain backward compatibility and production stability.

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

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

frontend/src/pages/admin/SettingsPage.tsx

@@ -64,6 +64,7 @@ export const SettingsPage: React.FC = () => {
   const [securitySettings, setSecuritySettings] = useState({
     require_password: true,
     password_min_length: 8,
+    password_complexity: 'moderate',
     enable_2fa: false,
     session_timeout_minutes: 60,
     max_login_attempts: 5,
@@ -665,6 +666,25 @@ export const SettingsPage: React.FC = () => {
                   max="32"
                 />
               </div>
+
+              <div>
+                <label className="block text-sm font-medium text-neutral-700 mb-1">
+                  {t('settings.security.passwordComplexity')}
+                </label>
+                <select
+                  value={securitySettings.password_complexity}
+                  onChange={(e) => setSecuritySettings(prev => ({ ...prev, password_complexity: e.target.value }))}
+                  className="w-full px-3 py-2 border border-neutral-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-primary-500 focus:border-primary-500"
+                >
+                  <option value="simple">{t('settings.security.complexitySimple')}</option>
+                  <option value="moderate">{t('settings.security.complexityModerate')}</option>
+                  <option value="strong">{t('settings.security.complexityStrong')}</option>
+                  <option value="very_strong">{t('settings.security.complexityVeryStrong')}</option>
+                </select>
+                <p className="mt-1 text-sm text-neutral-600">
+                  {t('settings.security.passwordComplexityHelp')}
+                </p>
+              </div>
             </div>
           </Card>