feat: time-aware trade maturity classification

- Add _trade_maturity() helper: classifies trades by % of horizon elapsed
  (trop_tot <10%, debut 10-35%, mature 35-75%, fin_horizon >75%)
- Fix horizon_days fallback chain in log_trade_entries (default 30→90)
- journal.py: enrich each MTM trade with maturity dict + horizon_days
- reasoning.py: portfolio report segments trades by maturity; GPT-4o
  draws lessons only from matures (≥35% elapsed), never from trop_tot
- auto_cycle.py: 90d window, maturity-aware prompt with timing rules
- JournalDeBord.tsx: maturity badge with emoji, label, progress bar
  and day counter (Xj / Yj Z%) replacing plain days_held column

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

backend/routers/journal.py

@@ -1,7 +1,7 @@
 from fastapi import APIRouter
 from typing import Any, Dict, List
 import math
-from services.database import get_macro_regime_history, get_geo_alert_history, get_trade_entry_prices, reset_journal_history, _fetch_live_prices
+from services.database import get_macro_regime_history, get_geo_alert_history, get_trade_entry_prices, reset_journal_history, _fetch_live_prices, _trade_maturity
 
 
 def _sanitize(obj: Any) -> Any:
@@ -66,12 +66,16 @@ def trade_mtm(days: int = 30):
         except Exception:
             pass
 
+        horizon = e.get("horizon_days") or 90
+        maturity = _trade_maturity(days_held or 0, horizon)
+
         result.append({
             **e,
             "current_price": current_price,
             "pnl_pct": pnl_pct,
             "days_held": days_held,
             "direction": "bearish" if _is_bearish(e.get("strategy", "")) else "bullish",
+            "maturity": maturity,
         })
 
     return _sanitize({"trades": result, "days": days, "tickers_fetched": len(current_prices)})