feat: Implement Demo Test Tracker for Go-Live readiness assessment

NEW MODULE: demo_test_tracker.py
- DemoTestTracker class for comprehensive statistics collection
- TradeRecord dataclass for structured trade logging
- Automatic Win Rate, Profit Factor, Drawdown calculation
- Session-based and Signal Quality breakdown
- Error/Bug tracking
- Persistent JSON storage

GO-LIVE CRITERIA (configurable):
- min_trades: 50 trades required
- min_win_rate: 55%
- min_profit_factor: 1.3
- max_drawdown: 15%
- min_days: 14 days running
- max_errors: 5 critical errors
- min_sessions_tested: 2 different sessions

NEW NOTEBOOK CELLS:
- Cell 92: Performance Report & Go-Live Check
- Cell 93: MT5 History Sync (imports past trades)

FEATURES:
- print_report(): Full performance breakdown
- print_go_live_check(): Visual checklist with pass/fail
- get_daily_summary(): Quick daily stats
- sync_closed_trades_to_tracker(): Import from MT5 history

INTEGRATION:
- Added to Cell 78 (Advanced Optimizations)
- Tracks trades automatically after execution
- Persistent data in demo_test_stats.json

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dynamic_thresholds.json

@@ -1,10 +1,10 @@
 {
-  "timestamp": "2026-01-26T00:27:01.306793",
+  "timestamp": "2026-01-27T00:00:00.107097",
   "session_thresholds": {
     "asian": 60,
     "ny": 60,
-    "london": 75,
-    "overlap": 65
+    "london": 60,
+    "overlap": 60
   },
   "settings": {
     "lookback_trades": 20,