fix: 4 cycle errors — NameError _log, WHEAT/EUR/USD ticker normalization, 429 serial scoring

- auto_cycle.py: replace _log with logger (NameError at lines 484/489)
- auto_cycle.py: normalize underlying via _normalize_ticker before _resolve_ticker
  so WHEAT→ZW=F→WEAT and EUR/USD→EURUSD=X→FXE reach the IV watchlist correctly
- iv_engine.py: _resolve_ticker now strips slash-format forex (EUR/USD→EURUSD=X)
  before _PROXY lookup, fixing yfinance 500/404 spam from get_atm_iv
- database.py: _fetch in log_trade_entries uses _normalize_ticker (not _normalize_yf_ticker)
  so commodity aliases like WHEAT→ZW=F are applied at price-fetch time
- ai_analyzer.py: max_workers=1 for batch scorer — parallel workers both slept and
  retried simultaneously after 429, causing repeated bursts; sequential fixes the pattern
- journal.py + JournalDeBord.tsx: add price_warning field (no_price_data/no_entry_price/
  no_live_price) with visible ⚠ badge and amber color on affected ticker/price cells

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

backend/services/database.py

@@ -940,7 +940,7 @@ def log_trade_entries(run_id: str, scored_patterns: List[Dict[str, Any]], quotes
             from concurrent.futures import ThreadPoolExecutor, as_completed
 
             def _fetch(ticker: str):
-                normalized = _normalize_yf_ticker(ticker)
+                normalized = _normalize_ticker(ticker)  # handles WHEAT→ZW=F, EUR/USD→EURUSD=X, etc.
                 try:
                     # Use yf.download() — fresh HTTP request, no in-process Ticker cache
                     for kwargs in [