Add persistent learning data and PnL display

- Created persistent learning status API with trading statistics
- Added comprehensive PnL and win rate display to AI Learning panel
- Implemented trading stats tracking with win/loss ratios
- Added persistent data storage for historical trading performance
- Enhanced learning panel with real-time trading metrics
- Fixed learning data visibility when bot is not running
- Added sample trading data for demonstration

data/learning-persistent.json

@@ -0,0 +1,53 @@
+{
+  "totalTrades": 47,
+  "winningTrades": 28,
+  "losingTrades": 19,
+  "totalPnL": 342.75,
+  "winRate": 59.57,
+  "avgWinAmount": 18.45,
+  "avgLossAmount": -12.30,
+  "bestTrade": 89.50,
+  "worstTrade": -35.20,
+  "learningDecisions": 156,
+  "aiEnhancements": 23,
+  "riskThresholds": {
+    "emergency": 3,
+    "risk": 5,
+    "mediumRisk": 8
+  },
+  "lastUpdated": "2025-07-27T10:45:00.000Z",
+  "systemStatus": "learning",
+  "dataCollected": true,
+  "recentTrades": [
+    {
+      "id": "trade_1753612001_abc123",
+      "symbol": "SOLUSD",
+      "type": "LONG",
+      "entry": 186.45,
+      "exit": 189.20,
+      "pnl": 15.75,
+      "outcome": "WIN",
+      "timestamp": "2025-07-27T09:30:00.000Z"
+    },
+    {
+      "id": "trade_1753612002_def456", 
+      "symbol": "SOLUSD",
+      "type": "LONG",
+      "entry": 184.80,
+      "exit": 182.15,
+      "pnl": -8.95,
+      "outcome": "LOSS",
+      "timestamp": "2025-07-27T08:15:00.000Z"
+    },
+    {
+      "id": "trade_1753612003_ghi789",
+      "symbol": "SOLUSD", 
+      "type": "LONG",
+      "entry": 187.30,
+      "exit": 195.80,
+      "pnl": 42.50,
+      "outcome": "WIN",
+      "timestamp": "2025-07-27T07:45:00.000Z"
+    }
+  ]
+}