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/app/api/routes/trading.py

@@ -0,0 +1,27 @@
+from typing import List
+from fastapi import APIRouter, HTTPException
+from app.models.enums import StrategyEnum
+from app.models.schemas import StrategyStatus
+from app.services import StrategyService
+
+router = APIRouter()
+strategy_service = StrategyService()
+
+
+@router.get("/strategies", response_model=List[StrategyStatus])
+async def get_strategies():
+    return await strategy_service.get_all_strategies()
+
+
+@router.post("/strategies")
+async def toggle_strategy(strategy: StrategyEnum, action: str):
+    if action not in ["start", "stop"]:
+        raise HTTPException(status_code=400, detail="Action must be 'start' or 'stop'")
+
+    status = await strategy_service.toggle_strategy(strategy, action)
+    return {"status": status}
+
+
+@router.get("/positions")
+async def get_positions():
+    return {"positions": [], "total": 0}