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/ml/features/__init__.py

@@ -0,0 +1,53 @@
+from app.ml.features.lag_features import add_lag_features
+from app.ml.features.rolling_features import add_rolling_features
+from app.ml.features.time_features import add_time_features
+from app.ml.features.regional_features import add_regional_features
+from app.ml.features.battery_features import add_battery_features
+from typing import List, Optional
+import pandas as pd
+
+
+def build_price_features(
+    df: pd.DataFrame,
+    price_col: str = "real_time_price",
+    lags: Optional[List[int]] = None,
+    windows: Optional[List[int]] = None,
+    regions: Optional[List[str]] = None,
+    include_time: bool = True,
+    include_regional: bool = True,
+) -> pd.DataFrame:
+    if lags is None:
+        lags = [1, 5, 10, 15, 30, 60]
+
+    if windows is None:
+        windows = [5, 10, 15, 30, 60]
+
+    result = df.copy()
+
+    if price_col in result.columns:
+        result = add_lag_features(result, price_col, lags)
+        result = add_rolling_features(result, price_col, windows)
+
+    if include_time and "timestamp" in result.columns:
+        result = add_time_features(result)
+
+    if include_regional and regions:
+        result = add_regional_features(result, regions)
+
+    return result
+
+
+def build_battery_features(
+    df: pd.DataFrame,
+    price_df: pd.DataFrame,
+    battery_col: str = "charge_level_mwh",
+    capacity_col: str = "capacity_mwh",
+    timestamp_col: str = "timestamp",
+    battery_id_col: str = "battery_id",
+) -> pd.DataFrame:
+    result = df.copy()
+    result = add_battery_features(result, price_df, battery_col, capacity_col, timestamp_col, battery_id_col)
+    return result
+
+
+__all__ = ["build_price_features", "build_battery_features"]