feat: auth middleware, brain data layer, Valkey queue (P1-002/003/004) (#71)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/gateway/src/auth/auth.module.ts

@@ -0,0 +1,26 @@
+import { Global, Module } from '@nestjs/common';
+import { createAuth, type Auth } from '@mosaic/auth';
+import type { Db } from '@mosaic/db';
+import { DB } from '../database/database.module.js';
+import { AuthController } from './auth.controller.js';
+
+export const AUTH = 'AUTH';
+
+@Global()
+@Module({
+  providers: [
+    {
+      provide: AUTH,
+      useFactory: (db: Db): Auth =>
+        createAuth({
+          db,
+          baseURL: process.env['BETTER_AUTH_URL'] ?? 'http://localhost:4000',
+          secret: process.env['BETTER_AUTH_SECRET'],
+        }),
+      inject: [DB],
+    },
+  ],
+  controllers: [AuthController],
+  exports: [AUTH],
+})
+export class AuthModule {}