chore: migrate to pnpm workspaces monorepo with Turborepo

- Restructure directories: apps/api, apps/admin, apps/website
- Add root pnpm-workspace.yaml, turbo.json, .prettierrc, .gitignore
- Rename packages to @inkreach/api, @inkreach/admin, @inkreach/website
- Add shared packages: packages/tsconfig, packages/shared-types
- Add pnpm.onlyBuiltDependencies for native builds
- Update docs: README.md, structs.md
- All three projects build successfully

apps/api/src/main.ts

@@ -0,0 +1,72 @@
+import { NestFactory } from '@nestjs/core';
+import { ValidationPipe } from '@nestjs/common';
+import { SwaggerModule, DocumentBuilder } from '@nestjs/swagger';
+import { json } from 'express';
+import { AppModule } from './app.module';
+import { HttpExceptionFilter } from './common/filters/http-exception.filter';
+import { TransformInterceptor } from './common/interceptors/transform.interceptor';
+
+async function bootstrap() {
+  const app = await NestFactory.create(AppModule, { bodyParser: false });
+
+  // Replace Express's JSON parser with one that stringifies BigInt.
+  // Express's default `json()` throws "Do not know how to serialize a BigInt".
+  app.use(
+    json({
+      limit: '2mb',
+      reviver: (_key: string, value: unknown) => {
+        // If a numeric string would overflow the JS number range we keep
+        // it as a string; the JWT strategy / services expect bigints.
+        if (typeof value === 'string' && /^-?\d{16,}$/.test(value)) {
+          // Leave as string — services parse with BigInt().
+          return value;
+        }
+        return value;
+      },
+    }),
+  );
+
+  // CORS
+  app.enableCors({
+    origin: ['http://localhost:5173', 'http://localhost:3000'],
+    credentials: true,
+  });
+
+  // Global pipes
+  app.useGlobalPipes(
+    new ValidationPipe({
+      whitelist: true,
+      transform: true,
+      forbidNonWhitelisted: true,
+    }),
+  );
+
+  // Global filters and interceptors
+  app.useGlobalFilters(new HttpExceptionFilter());
+  app.useGlobalInterceptors(new TransformInterceptor());
+
+  // Swagger
+  const config = new DocumentBuilder()
+    .setTitle('InkReach Product Center API')
+    .setDescription('Backend API for InkReach Product Center')
+    .setVersion('1.0')
+    .addBearerAuth()
+    .build();
+
+  const document = SwaggerModule.createDocument(app, config);
+  SwaggerModule.setup('api/docs', app, document);
+
+  const port = process.env.PORT ?? 3001;
+  await app.listen(port);
+  console.log(`🚀 Application is running on: http://localhost:${port}`);
+  console.log(`📚 Swagger documentation: http://localhost:${port}/api/docs`);
+}
+
+// Make JSON.stringify aware of BigInt so outgoing responses containing
+// primary keys (`BigInt` columns) don't blow up. BigInts are serialized
+// as their decimal string — clients should parse them with BigInt().
+(BigInt.prototype as unknown as { toJSON: () => string }).toJSON = function () {
+  return this.toString();
+};
+
+bootstrap();