Fix XAU/USD display name, pip value, and invalid symbol validation

- config.py: add XAU/USD and XAG/USD to SYMBOL_DISPLAY; add PIP_VALUES
  map for commodities (gold pip = $0.01, not $0.0001)
- data_provider.py: use PIP_VALUES in get_pair_info so gold trade setup
  shows correct pip counts instead of 269,000 pips for a $27 SL
- main.py: validate symbols in symbol_from_name — rejects non-alpha
  inputs like '15M' with a helpful hint to use --timeframe instead

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config.py

@@ -48,7 +48,7 @@ CROSS_PAIRS = [
     "EURCHF=X", "CADJPY=X",
 ]
 
-# Yahoo Finance symbol mapping for display
+# Symbol display names
 SYMBOL_DISPLAY = {
     "EURUSD=X": "EUR/USD", "GBPUSD=X": "GBP/USD",
     "USDJPY=X": "USD/JPY", "USDCHF=X": "USD/CHF",
@@ -57,6 +57,15 @@ SYMBOL_DISPLAY = {
     "EURJPY=X": "EUR/JPY", "GBPJPY=X": "GBP/JPY",
     "AUDJPY=X": "AUD/JPY", "EURCHF=X": "EUR/CHF",
     "CADJPY=X": "CAD/JPY",
+    # Commodities
+    "XAUUSD=X": "XAU/USD", "XAGUSD=X": "XAG/USD",
+}
+
+# Pip values per symbol (used for trade setup risk/reward in pips)
+# Commodities and JPY pairs differ from the standard 0.0001 forex pip
+PIP_VALUES = {
+    "XAUUSD=X": 0.01,   # Gold: 1 pip = $0.01
+    "XAGUSD=X": 0.001,  # Silver: 1 pip = $0.001
 }