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/prisma/prisma.service.spec.ts

@@ -0,0 +1,31 @@
+import { PrismaService } from './prisma.service';
+import { Test } from '@nestjs/testing';
+
+describe('PrismaService', () => {
+  let service: PrismaService;
+
+  beforeAll(async () => {
+    const moduleRef = await Test.createTestingModule({
+      providers: [PrismaService],
+    }).compile();
+
+    service = moduleRef.get(PrismaService);
+    await service.onModuleInit();
+  });
+
+  afterAll(async () => {
+    await service.onModuleDestroy();
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+
+  it('should be able to run a trivial query against the database', async () => {
+    // Execute a raw query that does not depend on application tables
+    const result = await service.$queryRaw<Array<{ now: Date }>>`SELECT now() AS now`;
+    expect(Array.isArray(result)).toBe(true);
+    expect(result.length).toBe(1);
+    expect(result[0].now).toBeInstanceOf(Date);
+  });
+});