Initial scaffold: unified customer/insurance/utilities platform

Next.js + NestJS + Prisma (MySQL) monorepo replacing the legacy PHP
internal app. Includes a session-based auth module with Argon2 password
hashing and global input validation (replacing the old app's SQL
injection and plaintext password comparison), the full target Prisma
schema for customers/insurance/utilities/shared ledger/bank register,
Docker Compose + Dockerfiles, and an Access-to-staging migration
pipeline (migration/) already run against the real source databases.

See PLAN.md and RESUME.md for the full architecture and session history.

apps/api/src/app.module.ts

@@ -0,0 +1,17 @@
+import { Module } from "@nestjs/common";
+import { ConfigModule } from "@nestjs/config";
+import { PrismaModule } from "./prisma/prisma.module";
+import { UsersModule } from "./users/users.module";
+import { AuthModule } from "./auth/auth.module";
+import { AppController } from "./app.controller";
+
+@Module({
+  imports: [
+    ConfigModule.forRoot({ isGlobal: true }),
+    PrismaModule,
+    UsersModule,
+    AuthModule,
+  ],
+  controllers: [AppController],
+})
+export class AppModule {}