fix: V5.2 TP/SL parameters - wider stops for better risk/reward

V5.2: SL=3.0×ATR, TP1=2.0×ATR, TP2=4.5×ATR
V5.1: SL=2.0×ATR, TP1=1.5×ATR, TP2=3.0×ATR (unchanged)

Expected improvement: win/loss ratio 0.72→0.84, breakeven winrate 58%→54%

backend/ecosystem.dev.config.js

@@ -0,0 +1,13 @@
+module.exports = {
+  apps: [{
+    name: "arb-dev-signal",
+    script: "signal_engine.py",
+    interpreter: "python3",
+    cwd: "/root/Projects/arbitrage-engine/backend",
+    env: {
+      PG_HOST: "34.85.117.248",
+      CLOUD_PG_HOST: "34.85.117.248",
+      CLOUD_PG_ENABLED: "true"
+    }
+  }]
+};

backend/paper_config.json

@@ -0,0 +1,12 @@
+{
+  "enabled": true,
+  "enabled_strategies": ["v52_8signals"],
+  "initial_balance": 10000,
+  "risk_per_trade": 0.02,
+  "max_positions": 4,
+  "tier_multiplier": {
+    "light": 0.5,
+    "standard": 1.0,
+    "heavy": 1.5
+  }
+}

backend/strategies/v52_8signals.json

@@ -11,9 +11,9 @@
   },
   "accel_bonus": 5,
   "tp_sl": {
-    "sl_multiplier": 2.0,
+    "sl_multiplier": 3.0,
-    "tp1_multiplier": 1.5,
+    "tp1_multiplier": 2.0,
-    "tp2_multiplier": 3.0
+    "tp2_multiplier": 4.5
   },
   "signals": ["cvd", "p99", "accel", "ls_ratio", "oi", "coinbase_premium", "funding_rate", "liquidation"]
 }