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/settings.py

@@ -0,0 +1,26 @@
+from fastapi import APIRouter
+from app.config import settings
+from app.models.schemas import AppSettings
+
+router = APIRouter()
+
+
+@router.get("", response_model=AppSettings)
+async def get_settings():
+    return AppSettings(
+        battery_min_reserve=settings.BATTERY_MIN_RESERVE,
+        battery_max_charge=settings.BATTERY_MAX_CHARGE,
+        arbitrage_min_spread=settings.ARBITRAGE_MIN_SPREAD,
+        mining_margin_threshold=settings.MINING_MARGIN_THRESHOLD,
+    )
+
+
+@router.post("")
+async def update_settings(settings_update: dict):
+    updated_fields = []
+    for key, value in settings_update.items():
+        if hasattr(settings, key.upper()):
+            setattr(settings, key.upper(), value)
+            updated_fields.append(key)
+
+    return {"message": "Settings updated", "updated_fields": updated_fields}