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>

backend/app/main.py

@@ -0,0 +1,31 @@
+from fastapi import FastAPI
+from starlette.middleware.sessions import SessionMiddleware
+
+from app.config import settings
+from app.routers import auth, health, rooms
+from app.ws.chat import router as ws_router
+from app.ws.connection_manager import ConnectionManager
+
+
+def create_app() -> FastAPI:
+    app = FastAPI(title="KeepItTalking")
+
+    app.add_middleware(
+        SessionMiddleware,
+        secret_key=settings.session_secret,
+        same_site="lax",
+        https_only=settings.session_https_only,
+        max_age=settings.session_max_age_seconds,
+    )
+
+    app.state.connection_manager = ConnectionManager()
+
+    app.include_router(health.router)
+    app.include_router(auth.router)
+    app.include_router(rooms.router)
+    app.include_router(ws_router)
+
+    return app
+
+
+app = create_app()