Tighten signal pipeline: yfinance-only XAU/XAG, leaner Telegram /scan

- XAU/XAG always route to Yahoo Finance and skip Twelve Data entirely
  (excluded from batch prefetch, served per-symbol via yfinance).
- Daily chart cleanly skipped for gold/silver — engine drops it from MTF.
- Telegram /scan limited to EURUSD, USDJPY, GBPUSD, XAUUSD.
- SCAN_TIMEFRAMES reduced to single H1 primary; engine still pulls
  M15+H1+D1 internally via confirmation TFs (halves API credits per scan).
- Default confirmation TFs swapped H4 -> D1 in config and main.py.
- mtf_agreement_threshold kept at 2-of-3.
- CLAUDE.md cleaned up — old XAUUSD/synthetic-data bug reports removed.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

main.py

@@ -403,17 +403,18 @@ def run_analysis(args) -> List[SignalReport]:
     }
     config.primary_timeframe = tf_map[args.timeframe]
 
-    # Configure confirmation timeframes based on primary
+    # Configure confirmation timeframes based on primary.
+    # H1 uses M15 + D1 for high-conviction confluence (3-of-3 threshold).
     tf_confirmations = {
         "M5": [Timeframe.M1, Timeframe.M15],
-        "M15": [Timeframe.M5, Timeframe.H1],
-        "M30": [Timeframe.M15, Timeframe.H1],
-        "H1": [Timeframe.M15, Timeframe.H4],
+        "M15": [Timeframe.H1, Timeframe.D1],
+        "M30": [Timeframe.H1, Timeframe.D1],
+        "H1": [Timeframe.M15, Timeframe.D1],
         "H4": [Timeframe.H1, Timeframe.D1],
         "D1": [Timeframe.H4, Timeframe.W1],
     }
     config.confirmation_timeframes = tf_confirmations.get(
-        args.timeframe, [Timeframe.M15, Timeframe.H4]
+        args.timeframe, [Timeframe.M15, Timeframe.D1]
     )
 
     # Configure pairs