feat: Complete Sprints 3 & 4 - Email, Reschedule, OCR, Upload, Contact Forms

Sprint 3 - Crisis y Agenda (100%):
- Implement SMTP email service with nodemailer
- Create email templates (reschedule, daily agenda, course inquiry)
- Add appointment reschedule functionality with modal
- Add Google Calendar updateEvent function
- Create scheduled job for daily agenda email at 10 PM
- Add manual trigger endpoint for testing

Sprint 4 - Pagos y Roles (100%):
- Add Payment proof upload with OCR (tesseract.js, pdf-parse)
- Extract data from proofs (amount, date, reference, sender, bank)
- Create PaymentUpload component with drag & drop
- Add course contact form to /cursos page
- Update Services button to navigate to /servicios
- Add Reschedule button to Assistant and Therapist dashboards
- Add PaymentUpload component to Assistant dashboard
- Add eventId field to Appointment model
- Add OCR-extracted fields to Payment model
- Update Prisma schema and generate client
- Create API endpoints for reschedule, upload-proof, courses contact
- Create manual trigger endpoint for daily agenda job
- Initialize daily agenda job in layout.tsx

Dependencies added:
- nodemailer, node-cron, tesseract.js, sharp, pdf-parse, @types/nodemailer

Files created/modified:
- src/infrastructure/email/smtp.ts
- src/lib/email/templates/*
- src/jobs/send-daily-agenda.ts
- src/app/api/calendar/reschedule/route.ts
- src/app/api/payments/upload-proof/route.ts
- src/app/api/contact/courses/route.ts
- src/app/api/jobs/trigger-agenda/route.ts
- src/components/dashboard/RescheduleModal.tsx
- src/components/dashboard/PaymentUpload.tsx
- src/components/forms/CourseContactForm.tsx
- src/app/dashboard/asistente/page.tsx (updated)
- src/app/dashboard/terapeuta/page.tsx (updated)
- src/app/cursos/page.tsx (updated)
- src/components/layout/Services.tsx (updated)
- src/infrastructure/external/calendar.ts (updated)
- src/app/layout.tsx (updated)
- prisma/schema.prisma (updated)
- src/lib/validations.ts (updated)
- src/lib/env.ts (updated)

Tests:
- TypeScript typecheck: No errors
- ESLint: Only warnings (img tags, react-hooks)
- Production build: Successful

Documentation:
- Updated CHANGELOG.md with Sprint 3/4 changes
- Updated PROGRESS.md with 100% completion status
- Updated TASKS.md with completed tasks

src/infrastructure/email/smtp.ts

@@ -0,0 +1,95 @@
+import nodemailer from "nodemailer";
+import { getEnv } from "@/lib/env";
+import { getRescheduleConfirmationTemplate } from "@/lib/email/templates/reschedule-confirmation";
+import { getDailyAgendaTemplate } from "@/lib/email/templates/daily-agenda";
+import { getCourseInquiryTemplate } from "@/lib/email/templates/course-inquiry";
+
+let transporter: nodemailer.Transporter | null = null;
+
+function getTransporter(): nodemailer.Transporter {
+  if (transporter) {
+    return transporter;
+  }
+
+  const env = getEnv();
+
+  transporter = nodemailer.createTransport({
+    host: env.SMTP_HOST,
+    port: env.SMTP_PORT,
+    secure: false,
+    auth: {
+      user: env.SMTP_USER,
+      pass: env.SMTP_PASS,
+    },
+    pool: true,
+    maxConnections: 5,
+    maxMessages: 100,
+  });
+
+  return transporter;
+}
+
+export async function sendEmail(to: string, subject: string, html: string): Promise<void> {
+  const env = getEnv();
+  const transporter = getTransporter();
+
+  const mailOptions = {
+    from: `"${env.SMTP_FROM_NAME}" <${env.SMTP_FROM_EMAIL}>`,
+    to,
+    subject,
+    html,
+  };
+
+  let retries = 0;
+  const maxRetries = 3;
+
+  while (retries < maxRetries) {
+    try {
+      await transporter.sendMail(mailOptions);
+      console.log(`[SMTP] Email sent to ${to}`);
+      return;
+    } catch (error) {
+      retries++;
+      if (retries === maxRetries) {
+        console.error(`[SMTP] Failed to send email after ${maxRetries} retries:`, error);
+        throw error;
+      }
+      const delay = Math.pow(2, retries) * 1000;
+      await new Promise((resolve) => setTimeout(resolve, delay));
+    }
+  }
+}
+
+export async function sendRescheduleConfirmation(
+  to: string,
+  patientName: string,
+  oldDate: Date,
+  newDate: Date
+): Promise<void> {
+  const html = getRescheduleConfirmationTemplate(patientName, oldDate, newDate);
+  await sendEmail(to, "Confirmación de Cambio de Cita - Gloria Niño Terapia", html);
+}
+
+export async function sendDailyAgenda(to: string, appointments: any[]): Promise<void> {
+  const html = getDailyAgendaTemplate(appointments);
+  const tomorrow = new Date();
+  tomorrow.setDate(tomorrow.getDate() + 1);
+  const formattedDate = tomorrow.toLocaleDateString("es-MX", {
+    weekday: "long",
+    year: "numeric",
+    month: "long",
+    day: "numeric",
+  });
+  await sendEmail(to, `📅 Agenda para el día ${formattedDate}`, html);
+}
+
+export async function sendCourseInquiry(
+  to: string,
+  name: string,
+  email: string,
+  course: string,
+  message: string
+): Promise<void> {
+  const html = getCourseInquiryTemplate(name, email, course, message);
+  await sendEmail(to, `🎓 Nueva Consulta sobre Cursos - ${course}`, html);
+}