Strip backtesting, rebalance indicator weights toward leading signals

Remove backtest.py, backtest_gpu.py, metrics.py, local CSV data,
Dukascopy loader, and all backtest CLI modes from main.py. Rebalance
engine weights: leading indicators (divergence, RSI, stochastic, BB)
now carry 66% of signal weight vs 34% for lagging (EMA, MACD). Add
ws_twelvedata.py for live tick streaming. Drop pyarrow and tqdm deps.

signal_aggregator.py

@@ -2,9 +2,7 @@
 ForexBot2 — Signal Aggregator
 ==============================
 Combines multi-timeframe technical analysis with optional news context
-into a graded actionable signal. Same code path is used for live mode
-and walk-forward backtesting; the only difference is whether the input
-OHLCV is fetched live or sliced from a pre-loaded historical buffer.
+into a graded actionable signal.
 """
 
 import logging
@@ -79,10 +77,7 @@ class SignalReport:
 
 
 class SignalAggregator:
-    """
-    Master aggregator. Designed so the backtester can drive it bar-by-bar
-    via `analyze_from_dataframes` without re-fetching from the API.
-    """
+    """Master aggregator for live signal analysis."""
 
     def __init__(self, config: PlatformConfig):
         self.config = config