Phase 1: auth, room CRUD, WebSocket chat, PWA frontend

Invite-only FastAPI + SQLAlchemy(async) + Postgres backend (session-cookie
auth via CLI-provisioned accounts, open-room CRUD, single-instance /ws/chat)
and a React + Vite PWA frontend (login, room list, chat view). Backend tests
pass against a local Postgres DB. See README.md and backend/README.md for
setup, and ARCHITECTURE.md for the full phased design.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/api/auth.ts

@@ -0,0 +1,21 @@
+import { apiFetch } from './client'
+import type { User } from '../types'
+
+// No register() here: this is an invite-only site. Accounts are created by
+// an operator via the backend CLI (`python -m app.cli create-user`), not
+// through a public endpoint.
+
+export function login(usernameOrEmail: string, password: string): Promise<User> {
+  return apiFetch<User>('/api/auth/login', {
+    method: 'POST',
+    body: JSON.stringify({ username_or_email: usernameOrEmail, password }),
+  })
+}
+
+export function logout(): Promise<void> {
+  return apiFetch<void>('/api/auth/logout', { method: 'POST' })
+}
+
+export function me(): Promise<User> {
+  return apiFetch<User>('/api/auth/me')
+}