Refactor monolithic modules and harden booking, email, and auth infrastructure.

Split oversized frontend API client, email service, and admin/booking pages into focused modules while preserving import surfaces, and add Redis-backed queues, stale booking cleanup, stronger auth, and scale deployment configs.

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

backend/src/db/index.ts

@@ -12,8 +12,11 @@ const dbType = process.env.DB_TYPE || 'sqlite';
 let db: ReturnType<typeof drizzleSqlite> | ReturnType<typeof drizzlePg>;
 
 if (dbType === 'postgres') {
+  // Cap connections per instance so that, when running multiple replicas,
+  // DB_POOL_MAX * replicas stays below the Postgres max_connections limit.
   const pool = new pg.Pool({
     connectionString: process.env.DATABASE_URL || 'postgresql://localhost:5432/spanglish',
+    max: Number(process.env.DB_POOL_MAX || 10),
   });
   db = drizzlePg(pool, { schema });
 } else {

backend/src/db/migrate.ts

@@ -432,6 +432,18 @@ async function migrate() {
       )
     `);
 
+    await (db as any).run(sql`
+      CREATE TABLE IF NOT EXISTS email_queue (
+        id TEXT PRIMARY KEY,
+        params TEXT NOT NULL,
+        status TEXT NOT NULL DEFAULT 'pending',
+        attempts INTEGER NOT NULL DEFAULT 0,
+        last_error TEXT,
+        created_at TEXT NOT NULL,
+        processed_at TEXT
+      )
+    `);
+
     // Site settings table
     await (db as any).run(sql`
       CREATE TABLE IF NOT EXISTS site_settings (
@@ -899,6 +911,18 @@ async function migrate() {
       )
     `);
 
+    await (db as any).execute(sql`
+      CREATE TABLE IF NOT EXISTS email_queue (
+        id UUID PRIMARY KEY,
+        params TEXT NOT NULL,
+        status VARCHAR(20) NOT NULL DEFAULT 'pending',
+        attempts INTEGER NOT NULL DEFAULT 0,
+        last_error TEXT,
+        created_at TIMESTAMP NOT NULL,
+        processed_at TIMESTAMP
+      )
+    `);
+
     // Site settings table
     await (db as any).execute(sql`
       CREATE TABLE IF NOT EXISTS site_settings (

backend/src/db/schema.ts

@@ -273,6 +273,18 @@ export const sqliteEmailSettings = sqliteTable('email_settings', {
   updatedAt: text('updated_at').notNull(),
 });
 
+// Durable email queue. Jobs survive process restarts; a startup recovery step
+// resets any 'processing' rows back to 'pending'.
+export const sqliteEmailQueue = sqliteTable('email_queue', {
+  id: text('id').primaryKey(),
+  params: text('params').notNull(), // JSON-encoded TemplateEmailJobParams
+  status: text('status', { enum: ['pending', 'processing', 'sent', 'failed'] }).notNull().default('pending'),
+  attempts: integer('attempts').notNull().default(0),
+  lastError: text('last_error'),
+  createdAt: text('created_at').notNull(),
+  processedAt: text('processed_at'),
+});
+
 // Legal Pages table for admin-editable legal content
 export const sqliteLegalPages = sqliteTable('legal_pages', {
   id: text('id').primaryKey(),
@@ -608,6 +620,18 @@ export const pgEmailSettings = pgTable('email_settings', {
   updatedAt: timestamp('updated_at').notNull(),
 });
 
+// Durable email queue. Jobs survive process restarts; a startup recovery step
+// resets any 'processing' rows back to 'pending'.
+export const pgEmailQueue = pgTable('email_queue', {
+  id: uuid('id').primaryKey(),
+  params: pgText('params').notNull(), // JSON-encoded TemplateEmailJobParams
+  status: varchar('status', { length: 20 }).notNull().default('pending'),
+  attempts: pgInteger('attempts').notNull().default(0),
+  lastError: pgText('last_error'),
+  createdAt: timestamp('created_at').notNull(),
+  processedAt: timestamp('processed_at'),
+});
+
 // Legal Pages table for admin-editable legal content
 export const pgLegalPages = pgTable('legal_pages', {
   id: uuid('id').primaryKey(),
@@ -695,6 +719,7 @@ export const auditLogs = dbType === 'postgres' ? pgAuditLogs : sqliteAuditLogs;
 export const emailTemplates = dbType === 'postgres' ? pgEmailTemplates : sqliteEmailTemplates;
 export const emailLogs = dbType === 'postgres' ? pgEmailLogs : sqliteEmailLogs;
 export const emailSettings = dbType === 'postgres' ? pgEmailSettings : sqliteEmailSettings;
+export const emailQueue = dbType === 'postgres' ? pgEmailQueue : sqliteEmailQueue;
 export const paymentOptions = dbType === 'postgres' ? pgPaymentOptions : sqlitePaymentOptions;
 export const eventPaymentOverrides = dbType === 'postgres' ? pgEventPaymentOverrides : sqliteEventPaymentOverrides;
 export const magicLinkTokens = dbType === 'postgres' ? pgMagicLinkTokens : sqliteMagicLinkTokens;