feat: add user authentication with separate login and register pages

- Custom User model with email as unique identifier (AUTH_USER_MODEL)

- POST /api/auth/register/ with email validation, password min 8 chars, duplicate rejection

- POST /api/auth/login/ returning JWT (access + refresh) tokens

- Passwords hashed via Django's make_password

- React LoginPage and RegisterPage with form validation

- AuthContext with useReducer for auth state management

- Axios API client with JWT token injection

- TypeScript conversion of frontend scaffold

web/src/services/authApi.ts

@@ -0,0 +1,55 @@
+import axios from "axios";
+
+const apiClient = axios.create({
+  baseURL: import.meta.env.VITE_API_URL || "http://localhost:8000",
+  headers: {
+    "Content-Type": "application/json",
+  },
+});
+
+// Attach access token to every request if present
+apiClient.interceptors.request.use((config) => {
+  const token = localStorage.getItem("access_token");
+  if (token && config.headers) {
+    config.headers.Authorization = `Bearer ${token}`;
+  }
+  return config;
+});
+
+export interface RegisterPayload {
+  email: string;
+  password: string;
+  password_confirm: string;
+  first_name?: string;
+  last_name?: string;
+}
+
+export interface LoginPayload {
+  email: string;
+  password: string;
+}
+
+export interface UserProfile {
+  id: number;
+  email: string;
+  first_name: string;
+  last_name: string;
+}
+
+export interface LoginResponse {
+  user: UserProfile;
+  access: string;
+  refresh: string;
+}
+
+export function registerUser(payload: RegisterPayload): Promise<UserProfile> {
+  return apiClient
+    .post<UserProfile>("/api/auth/register/", payload)
+    .then((res) => res.data);
+}
+
+export function loginUser(payload: LoginPayload): Promise<LoginResponse> {
+  return apiClient
+    .post<LoginResponse>("/api/auth/login/", payload)
+    .then((res) => res.data);
+}