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/Dockerfile

@@ -2,11 +2,11 @@ FROM node:20-alpine AS base
 
 WORKDIR /app
 
-COPY package.json ./
-RUN yarn install --frozen-lockfile
+COPY package*.json ./
+RUN npm ci
 
 COPY . .
 
 EXPOSE 3000
 
-CMD ["yarn", "dev"]
+CMD ["npm", "run", "dev"]