Add transactional emails: welcome, professional submission, status changes

- mail/mail.service.ts: MailService with HTML templates (welcome, submitted,
  approved, rejected, pending, deactivated). Silent if SMTP not configured.
- mail/mail.module.ts: global module so all services can inject MailService
- auth.service.ts: send welcome email on register()
- professionals.service.ts: notify admin on new submission; notify professional
  on approve/deny/deactivate/setPending

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

backend/src/professionals/professionals.service.ts

@@ -1,9 +1,10 @@
 import { Injectable, NotFoundException, BadRequestException, ForbiddenException } from '@nestjs/common';
 import { PrismaService } from '../prisma/prisma.service';
+import { MailService } from '../mail/mail.service';
 
 @Injectable()
 export class ProfessionalsService {
-  constructor(private prisma: PrismaService) {}
+  constructor(private prisma: PrismaService, private mail: MailService) {}
 
   async findAllActive(page = 1, limit = 20, city?: string) {
     const skip = (page - 1) * limit;
@@ -72,16 +73,20 @@ export class ProfessionalsService {
 
     if (!existing) {
       await this.prisma.users.update({ where: { id: userId }, data: { pro_state: 1 } });
-      return this.prisma.professionals.create({ data: { user_id: userId, is_active: false, ...data } });
+      const prof = await this.prisma.professionals.create({ data: { user_id: userId, is_active: false, ...data } });
+      const u = await this.prisma.users.findUnique({ where: { id: userId }, select: { name: true, email: true } });
+      if (u?.email) this.mail.sendProfessionalSubmitted(u.name || 'Usuario', u.email, data.profession || '').catch(() => {});
+      return prof;
     }
 
     // Re-submitting after rejection reset (pro_state=0): move back to pending
-    const user = await this.prisma.users.findUnique({ where: { id: userId }, select: { pro_state: true } });
+    const user = await this.prisma.users.findUnique({ where: { id: userId }, select: { pro_state: true, name: true, email: true } });
     if (user?.pro_state === 0) {
       await this.prisma.$transaction([
         this.prisma.professionals.update({ where: { user_id: userId }, data: { ...data, is_active: false } }),
         this.prisma.users.update({ where: { id: userId }, data: { pro_state: 1 } }),
       ]);
+      if (user.email) this.mail.sendProfessionalSubmitted(user.name || 'Usuario', user.email, data.profession || '').catch(() => {});
       return this.prisma.professionals.findUnique({ where: { user_id: userId } });
     }
 
@@ -155,15 +160,11 @@ export class ProfessionalsService {
     if (!prof) throw new NotFoundException('Profesional no encontrado');
 
     await this.prisma.$transaction([
-      this.prisma.professionals.update({
-        where: { id: professionalId },
-        data: { is_active: true },
-      }),
-      this.prisma.users.update({
-        where: { id: prof.user_id },
-        data: { pro_state: 2 },
-      }),
+      this.prisma.professionals.update({ where: { id: professionalId }, data: { is_active: true } }),
+      this.prisma.users.update({ where: { id: prof.user_id }, data: { pro_state: 2 } }),
     ]);
+    const u = await this.prisma.users.findUnique({ where: { id: prof.user_id }, select: { name: true, email: true } });
+    if (u?.email) this.mail.sendStatusChanged(u.name || 'Profesional', u.email, 'approved').catch(() => {});
     return { message: 'Profesional aprobado' };
   }
 
@@ -175,6 +176,8 @@ export class ProfessionalsService {
       this.prisma.professionals.update({ where: { id: professionalId }, data: { is_active: false, updated_at: new Date() } }),
       this.prisma.users.update({ where: { id: prof.user_id }, data: { pro_state: 3 } }),
     ]);
+    const u = await this.prisma.users.findUnique({ where: { id: prof.user_id }, select: { name: true, email: true } });
+    if (u?.email) this.mail.sendStatusChanged(u.name || 'Profesional', u.email, 'rejected').catch(() => {});
     return { message: 'Solicitud rechazada' };
   }
 
@@ -191,6 +194,8 @@ export class ProfessionalsService {
       this.prisma.professionals.update({ where: { id }, data: { is_active: false } }),
       this.prisma.users.update({ where: { id: prof.user_id }, data: { pro_state: 3 } }),
     ]);
+    const u = await this.prisma.users.findUnique({ where: { id: prof.user_id }, select: { name: true, email: true } });
+    if (u?.email) this.mail.sendStatusChanged(u.name || 'Profesional', u.email, 'deactivated').catch(() => {});
     return { message: 'Profesional desactivado' };
   }
 
@@ -201,6 +206,8 @@ export class ProfessionalsService {
       this.prisma.professionals.update({ where: { id }, data: { is_active: false } }),
       this.prisma.users.update({ where: { id: prof.user_id }, data: { pro_state: 1 } }),
     ]);
+    const u = await this.prisma.users.findUnique({ where: { id: prof.user_id }, select: { name: true, email: true } });
+    if (u?.email) this.mail.sendStatusChanged(u.name || 'Profesional', u.email, 'pending').catch(() => {});
     return { message: 'Profesional puesto en revisión' };
   }