Add FastAPI backend for energy trading system

Implements FastAPI backend with ML model support for energy trading,
including price prediction models and RL-based battery trading policy.
Features dashboard, trading, backtest, and settings API routes with
WebSocket support for real-time updates.

backend/pyproject.toml

@@ -0,0 +1,57 @@
+[build-system]
+requires = ["setuptools>=68.0", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "energy-trading-backend"
+version = "1.0.0"
+description = "FastAPI backend for energy trading system"
+requires-python = ">=3.10"
+dependencies = [
+    "fastapi>=0.104.0",
+    "uvicorn[standard]>=0.24.0",
+    "pydantic>=2.4.0",
+    "pydantic-settings>=2.0.0",
+    "pandas>=2.1.0",
+    "numpy>=1.24.0",
+    "pyarrow>=14.0.0",
+    "xgboost>=2.0.0",
+    "scikit-learn>=1.3.0",
+    "gymnasium>=0.29.0",
+    "stable-baselines3>=2.0.0",
+    "celery>=5.3.0",
+    "redis>=5.0.0",
+    "websockets>=12.0.0",
+    "sqlalchemy>=2.0.0",
+    "alembic>=1.12.0",
+    "python-multipart>=0.0.6",
+    "python-jose[cryptography]>=3.3.0",
+    "python-dotenv>=1.0.0",
+    "loguru>=0.7.0",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=7.4.0",
+    "pytest-asyncio>=0.21.0",
+    "httpx>=0.25.0",
+    "black>=23.0.0",
+    "ruff>=0.1.0",
+]
+
+[project.scripts]
+energy-train = "app.ml.training.cli:main"
+
+[tool.black]
+line-length = 100
+target-version = ['py310']
+
+[tool.ruff]
+line-length = 100
+select = ["E", "F", "I", "N", "W"]
+ignore = []
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+testpaths = ["tests"]
+python_files = ["test_*.py"]