chore(repo): restructure as monorepo with server and client workspaces

- move NestJS app into server/ subdirectory
- add client/ React+TypeScript (Vite) app with Hello World
- update docker-compose to build and run both services
- add root package.json declaring npm workspaces
- update .gitignore to cover node_modules and dist at all depths

server/test/auth.controller.spec.ts

@@ -0,0 +1,61 @@
+import { INestApplication } from "@nestjs/common";
+import request from "supertest";
+import { buildTestApp } from "./app.harness";
+
+/**
+ * Auth controller integration tests.
+ *
+ * The login endpoint requires a live browser + real key files, so it is not
+ * exercised here (those belong to e2e tests with real credentials).
+ * We cover the parts that can be tested without external dependencies.
+ */
+describe("AuthController", () => {
+  let app: INestApplication;
+
+  beforeAll(async () => {
+    app = await buildTestApp();
+  });
+
+  afterAll(async () => {
+    await app.close();
+  });
+
+  // ── GET /keys ──────────────────────────────────────────────────────────────
+
+  describe("GET /keys", () => {
+    it("returns 200 with a keys array", async () => {
+      const res = await request(app.getHttpServer()).get("/keys").expect(200);
+      expect(res.body).toHaveProperty("keys");
+      expect(Array.isArray(res.body.keys)).toBe(true);
+    });
+  });
+
+  // ── POST /login ────────────────────────────────────────────────────────────
+
+  describe("POST /login", () => {
+    it("returns 400 when body is empty", async () => {
+      await request(app.getHttpServer()).post("/login").send({}).expect(400);
+    });
+
+    it("returns 400 when key is missing", async () => {
+      await request(app.getHttpServer())
+        .post("/login")
+        .send({ environmentName: "test-env" })
+        .expect(400);
+    });
+
+    it("returns 400 when environmentName is missing", async () => {
+      await request(app.getHttpServer())
+        .post("/login")
+        .send({ key: "some-key" })
+        .expect(400);
+    });
+
+    it("returns 400 when key file does not exist", async () => {
+      await request(app.getHttpServer())
+        .post("/login")
+        .send({ key: "nonexistent-key", environmentName: "test-env" })
+        .expect(404); // NotFoundException for missing environment
+    });
+  });
+});