feat: Enhance ticketing system with categories, templates, SLA tracking, and fix frontend integration

- Add ticket categories (billing, technical, feature_request, etc.) with type-specific options
- Add TicketTemplate and CannedResponse models for quick ticket creation
- Implement SLA tracking with due_at and first_response_at fields
- Add is_platform_admin and is_customer helper functions to fix permission checks
- Register models in Django admin with filters and fieldsets
- Enhance signals with error handling for WebSocket notifications
- Fix frontend API URLs for templates and canned responses
- Update PlatformSupport page to use real ticketing API
- Add comprehensive i18n translations for all ticket fields

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

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

frontend/src/types.ts

@@ -179,9 +179,22 @@ export interface Metric {
 
 // --- Platform Types ---
 
-export type TicketType = 'PLATFORM' | 'CUSTOMER' | 'STAFF_REQUEST';
-export type TicketStatus = 'OPEN' | 'IN_PROGRESS' | 'RESOLVED' | 'CLOSED';
+export type TicketType = 'PLATFORM' | 'CUSTOMER' | 'STAFF_REQUEST' | 'INTERNAL';
+export type TicketStatus = 'OPEN' | 'IN_PROGRESS' | 'RESOLVED' | 'CLOSED' | 'AWAITING_RESPONSE';
 export type TicketPriority = 'LOW' | 'MEDIUM' | 'HIGH' | 'URGENT';
+export type TicketCategory =
+  | 'BILLING'
+  | 'TECHNICAL'
+  | 'FEATURE_REQUEST'
+  | 'ACCOUNT'
+  | 'APPOINTMENT'
+  | 'REFUND'
+  | 'COMPLAINT'
+  | 'GENERAL_INQUIRY'
+  | 'TIME_OFF'
+  | 'SCHEDULE_CHANGE'
+  | 'EQUIPMENT'
+  | 'OTHER';
 
 export interface TicketComment {
   id: string;
@@ -208,13 +221,43 @@ export interface Ticket {
   priority: TicketPriority;
   subject: string;
   description: string;
-  category?: string;
+  category: TicketCategory;
+  relatedAppointmentId?: string; // Appointment ID, optional
+  dueAt?: string; // Date string
+  firstResponseAt?: string; // Date string
+  isOverdue?: boolean;
   createdAt: string; // Date string
   updatedAt: string; // Date string
   resolvedAt?: string; // Date string
   comments?: TicketComment[]; // Nested comments
 }
 
+export interface TicketTemplate {
+  id: string;
+  tenant?: string; // Tenant ID, optional for platform templates
+  name: string;
+  description: string;
+  ticketType: TicketType;
+  category: TicketCategory;
+  defaultPriority: TicketPriority;
+  subjectTemplate: string;
+  descriptionTemplate: string;
+  isActive: boolean;
+  createdAt: string; // Date string
+}
+
+export interface CannedResponse {
+  id: string;
+  tenant?: string; // Tenant ID, optional for platform canned responses
+  title: string;
+  content: string;
+  category?: TicketCategory;
+  isActive: boolean;
+  useCount: number;
+  createdBy?: string; // User ID
+  createdAt: string; // Date string
+}
+
 export interface PlatformMetric {
   label: string;
   value: string;