Add MT5 safety tools to prevent MetaEditor freezes

- check-syntax.sh: Pre-compilation syntax checker for MT4→MT5 issues
- metaeditor-watchdog.sh: Auto-kills stuck MetaEditor processes
- safe-compile.sh: Wrapper with 2-minute timeout for compilations

These tools help prevent the container freeze that occurred when
trying to compile OrdersEA with 100 MT4 syntax errors.

scripts/metaeditor-watchdog.sh

@@ -0,0 +1,23 @@
+#!/bin/bash
+# Watchdog to kill stuck MetaEditor processes
+
+while true; do
+    # Find MetaEditor processes running for more than 5 minutes with high CPU
+    docker exec mt5 sh -c '
+        ps aux | grep metaeditor64 | grep -v grep | while read line; do
+            pid=$(echo $line | awk "{print \$2}")
+            cpu=$(echo $line | awk "{print \$3}")
+            time=$(echo $line | awk "{print \$10}")
+            # Kill if running more than 5 mins or using >50% CPU for >2 mins
+            if echo "$time" | grep -qE "[5-9]:[0-9]{2}|[0-9]{2,}:"; then
+                echo "Killing long-running MetaEditor: $pid (time: $time)"
+                kill -9 $pid 2>/dev/null
+            elif [ "${cpu%.*}" -gt 50 ] 2>/dev/null; then
+                echo "Killing high-CPU MetaEditor: $pid (CPU: $cpu%)"
+                kill -9 $pid 2>/dev/null
+            fi
+        done
+    ' 2>/dev/null
+    
+    sleep 60
+done