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/rooms.ts

@@ -0,0 +1,21 @@
+import { apiFetch } from './client'
+import type { Message, Room, RoomListItem } from '../types'
+
+export function listRooms(): Promise<RoomListItem[]> {
+  return apiFetch<RoomListItem[]>('/api/rooms')
+}
+
+export function createRoom(name: string, description?: string): Promise<Room> {
+  return apiFetch<Room>('/api/rooms', {
+    method: 'POST',
+    body: JSON.stringify({ name, description: description || null }),
+  })
+}
+
+export function joinRoom(roomId: string): Promise<Room> {
+  return apiFetch<Room>(`/api/rooms/${roomId}/join`, { method: 'POST' })
+}
+
+export function getRoomMessages(roomId: string): Promise<Message[]> {
+  return apiFetch<Message[]>(`/api/rooms/${roomId}/messages`)
+}