fix: align Flutter endpoints and model parsing with actual NestJS backend

- Auth: phone login → POST /auth/phone (direct, no OTP); link phone → POST /auth/verify-phone; add email → POST /auth/link-email
- Services: replace query-param paths with dedicated role endpoints (/services/me, /services/professional/requests, /services/professional, etc.)
- Services: PATCH /services/:id → PATCH /services/:id/status
- Calendar: → GET /services/professional/calendar
- Professionals: /users/professionals → /professionals (handles {data:[...]} response)
- Professional info: /professional-info/:id → /professionals/:id; PATCH → /professionals/me
- Comments: /comments?... → /comments/user/:id and /comments/professional/:id
- Chat: /chats → /chat; start chat → POST /chat/start/:professionalId; poll GET /chat/:chatId/messages; send → POST /chat/:chatId/message
- Cities: /cities → GET /locations/countries (parse nested countries→regions→cities)
- Profesional.fromDocument: null-safe fields; convert schedules array→Schedules, specializations array→name/picture lists, payment_methods object/array
- Usuario.fromDocument: null-safe professional_state and id
- UsuarioProfesional.fromDocument: handle backend format (users nested, professional at top level)
- ScheduleEntity.parseTime: handle ISO8601 time strings from backend
- MessageEntity.fromDocument: accept sender_id (backend) or owner_id (legacy)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/models/usuario_profesional.dart

@@ -30,9 +30,15 @@ class UsuarioProfesional {
   }
 
   static UsuarioProfesional fromDocument(Map<String, dynamic> doc) {
+    // Backend from /professionals returns professional at top level with 'users' nested
+    // Legacy format uses 'user' and 'professional_info' keys
+    final userDoc = (doc['users'] ?? doc['user']) as Map<String, dynamic>?;
+    final proDoc = doc.containsKey('professional_info')
+        ? doc['professional_info'] as Map<String, dynamic>
+        : doc;
     return UsuarioProfesional(
-      user: Usuario.fromDocument(doc['user'] as Map<String, dynamic>),
-      professionalInfo: Profesional.fromDocument(doc['professional_info'] as Map<String, dynamic>),
+      user: Usuario.fromDocument(userDoc ?? {}),
+      professionalInfo: Profesional.fromDocument(proDoc),
       averageScore: (doc['average_score'] as num?)?.toDouble() ?? 0.0,
     );
   }