Remove dead code: legacy config fields, unused helpers/imports, stray files

- Delete test_ws_dual.py (standalone probe, unused) and a stale tracked log
- config.py: drop MarketSession enum, is_jpy_pair, candle_buffer_seconds,
  and the never-read legacy SignalConfig/XauStrategyConfig fields
- data_provider.py: drop uncalled get_latest_price/get_spread_estimate
- Remove unused imports (engine, telegram_bot, main, news_engine)
- test_all.py: drop/trim the corresponding defaults assertions (199 tests)
- CLAUDE.md updated to match

Zero behavior change: no production code read any removed field
(verified reference-by-reference); suite green at 199/199.

Claude-Session: https://claude.ai/code/session_01VPNF37MP9Kuv62B1VBrZ1b

data_provider.py

@@ -204,25 +204,6 @@ class ForexDataProvider:
         logger.info(f"Cache cleared: {count} entries wiped")
         return count
 
-    def get_latest_price(self, symbol: str = XAUUSD) -> Optional[float]:
-        try:
-            df = self.fetch_ohlcv(symbol, Timeframe.M5, lookback_days=1)
-            if df is not None and not df.empty:
-                return float(df["Close"].iloc[-1])
-        except Exception:
-            pass
-        return None
-
-    def get_spread_estimate(self, symbol: str = XAUUSD) -> float:
-        try:
-            df = self.fetch_ohlcv(symbol, Timeframe.M5, lookback_days=1)
-            if df is not None and not df.empty:
-                return float((df["High"] - df["Low"]).median())
-        except Exception:
-            pass
-        info = PAIR_INFO.get(symbol, PAIR_INFO[XAUUSD])
-        return info["pip_value"]
-
     def get_pair_info(self, symbol: str = XAUUSD) -> Dict:
         info = PAIR_INFO.get(symbol, PAIR_INFO[XAUUSD])
         return {"symbol": symbol, **info}