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/pyproject.toml

@@ -0,0 +1,37 @@
+[project]
+name = "chatapp"
+version = "0.1.0"
+description = "KeepItTalking chat service backend"
+requires-python = ">=3.11"
+dependencies = [
+    "fastapi>=0.115",
+    "uvicorn[standard]>=0.32",
+    "sqlalchemy>=2.0.36",
+    "asyncpg>=0.30",
+    "alembic>=1.14",
+    "pydantic>=2.9",
+    "pydantic[email]>=2.9",
+    "pydantic-settings>=2.6",
+    "argon2-cffi>=23.1",
+    "itsdangerous>=2.2",
+]
+
+[project.scripts]
+chatapp-create-user = "app.cli:main"
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8",
+    "pytest-asyncio>=0.24",
+    "httpx>=0.27",
+]
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.hatch.build.targets.wheel]
+packages = ["app"]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"