chore: initial project setup with backend, frontend, Android app, and CI/CD

Add complete NexaMFA push MFA system with:
- FastAPI backend with PostgreSQL, Redis, OIDC provider, and Prometheus metrics
- React TypeScript admin console
- Android Kotlin/Jetpack Compose app with biometric authentication
- Docker Compose deployment configuration
- Gitea CI workflow for backend, frontend, and Android builds
- Environment configuration template with security settings
- Documentation for security model, deployment

backend/pyproject.toml

@@ -0,0 +1,39 @@
+[project]
+name = "nexamfa-backend"
+version = "0.1.0"
+description = "Self-hosted Push MFA service with OIDC provider support"
+requires-python = ">=3.12"
+dependencies = [
+  "alembic==1.13.2",
+  "asyncpg==0.29.0",
+  "cryptography==42.0.8",
+  "fastapi==0.111.0",
+  "google-auth==2.30.0",
+  "httpx==0.27.0",
+  "prometheus-client==0.20.0",
+  "pydantic-settings==2.3.4",
+  "pyjwt[crypto]==2.8.0",
+  "python-jose[cryptography]==3.3.0",
+  "python-multipart==0.0.9",
+  "qrcode[pil]==7.4.2",
+  "redis==5.0.7",
+  "slowapi==0.1.9",
+  "sqlalchemy[asyncio]==2.0.31",
+  "uvicorn[standard]==0.30.1"
+]
+
+[project.optional-dependencies]
+test = [
+  "aiosqlite==0.20.0",
+  "pytest==8.2.2",
+  "pytest-asyncio==0.23.7",
+  "pytest-cov==5.0.0"
+]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py312"