Email queue + async sending; legal settings and placeholders

- Add in-memory email queue with rate limiting (MAX_EMAILS_PER_HOUR)
- Bulk send to event attendees now queues and returns immediately
- Frontend shows 'Emails are being sent in the background'
- Legal pages, settings, and placeholders updates

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/lib/api.ts

@@ -384,7 +384,7 @@ export const emailsApi = {
     customVariables?: Record<string, any>;
     recipientFilter?: 'all' | 'confirmed' | 'pending' | 'checked_in';
   }) =>
-    fetchApi<{ success: boolean; sentCount: number; failedCount: number; errors: string[] }>(
+    fetchApi<{ success: boolean; queuedCount: number; error?: string }>(
       `/api/emails/send/event/${eventId}`,
       {
         method: 'POST',
@@ -1008,6 +1008,34 @@ export const siteSettingsApi = {
     }),
 };
 
+// ==================== Legal Settings API ====================
+
+export interface LegalSettingsData {
+  id?: string;
+  companyName?: string | null;
+  legalEntityName?: string | null;
+  rucNumber?: string | null;
+  companyAddress?: string | null;
+  companyCity?: string | null;
+  companyCountry?: string | null;
+  supportEmail?: string | null;
+  legalEmail?: string | null;
+  governingLaw?: string | null;
+  jurisdictionCity?: string | null;
+  updatedAt?: string;
+  updatedBy?: string;
+}
+
+export const legalSettingsApi = {
+  get: () => fetchApi<{ settings: LegalSettingsData }>('/api/legal-settings'),
+
+  update: (data: Partial<LegalSettingsData>) =>
+    fetchApi<{ settings: LegalSettingsData; message: string }>('/api/legal-settings', {
+      method: 'PUT',
+      body: JSON.stringify(data),
+    }),
+};
+
 // ==================== Legal Pages Types ====================
 
 export interface LegalPage {