Scaffold project layout, DB schema and settings

Package skeleton, pyproject/alembic config, env-driven settings
(app/config.py), and the SQLAlchemy models + initial Alembic migration
covering users, UTXO events, rounds/participants, round config,
pending transactions, withdrawals and the audit log.

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

pyproject.toml

@@ -0,0 +1,30 @@
+[project]
+name = "plm-lottery"
+version = "0.1.0"
+requires-python = ">=3.12"
+dependencies = [
+    "fastapi>=0.115",
+    "uvicorn[standard]>=0.32",
+    "sqlalchemy>=2.0",
+    "aiosqlite>=0.20",
+    "alembic>=1.13",
+    "pydantic-settings>=2.6",
+    "argon2-cffi>=23.1",
+    "pyjwt>=2.7",
+    "cryptography>=43.0",
+    "embit>=0.7",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8.3",
+    "pytest-asyncio>=0.24",
+    "httpx>=0.27",
+]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+
+[tool.setuptools.packages.find]
+include = ["app*"]