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>

telegram_bot.py

@@ -40,7 +40,11 @@ logger = logging.getLogger(__name__)
 
 # ── Config ──────────────────────────────────────────────────────────
 
-SCAN_TIMEFRAMES = ["M15", "H1"]
+SCAN_TIMEFRAMES = ["H1"]  # engine pulls M15 + H1 + D1 via confirmations
+
+# Pairs analyzed by the /scan command. Limited to the most liquid majors
+# plus gold to keep credits low and signal quality high.
+SCAN_PAIRS = ["EURUSD=X", "USDJPY=X", "GBPUSD=X", "XAUUSD=X"]
 
 _TF_MAP = {
     "M5":  Timeframe.M5,  "M15": Timeframe.M15,
@@ -268,7 +272,7 @@ class ForexTelegramBot:
     def _build_config(self, tf: str, pairs: List[str]) -> PlatformConfig:
         cfg = PlatformConfig()
         cfg.primary_timeframe       = _TF_MAP[tf]
-        cfg.confirmation_timeframes = _TF_CONFIRMATIONS.get(tf, [Timeframe.M15, Timeframe.H4])
+        cfg.confirmation_timeframes = _TF_CONFIRMATIONS.get(tf, [Timeframe.M15, Timeframe.D1])
         cfg.watch_pairs             = list(pairs)
         return cfg
 
@@ -418,7 +422,7 @@ class ForexTelegramBot:
                 pass
 
         try:
-            results_by_tf = await self._analyze_all_tfs(list(MAJOR_PAIRS), progress=progress)
+            results_by_tf = await self._analyze_all_tfs(list(SCAN_PAIRS), progress=progress)
             now_str = _now_est()
 
             # Best grade per pair across all TFs