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/iv_engine.py

@@ -50,7 +50,13 @@ IV_WATCHLIST = [
 
 def _resolve_ticker(ticker: str) -> str:
     """Return the optionable proxy ticker for a given symbol."""
-    return _PROXY.get(ticker.upper(), ticker.upper())
+    t = ticker.upper().strip()
+    # Normalize slash-format forex (EUR/USD → EURUSD=X) before proxy lookup
+    if '/' in t:
+        parts = t.split('/')
+        if len(parts) == 2 and all(p.isalpha() for p in parts):
+            t = parts[0] + parts[1] + '=X'
+    return _PROXY.get(t, t)
 
 
 def _get_current_price(t: yf.Ticker) -> Optional[float]: