Document MT5 freeze analysis and solutions

SESSION_SAVE_2026-03-22.md

@@ -247,3 +247,50 @@ This will:
 | `IsOptimization()` | `MQLInfoInteger(MQL_OPTIMIZATION)` |
 
 **Commit:** `c415cd9`
+
+---
+
+## MT5 Freeze Analysis & Solutions
+**Date:** March 24, 2026
+
+### Why Did It Freeze?
+
+**Root Cause:** OrdersEA.mq5 was an **MT4 file disguised as MT5**
+
+| Issue | Details |
+|-------|---------|
+| File Type | MT4 syntax with .mq5 extension |
+| Syntax Errors | 100 errors detected by MetaEditor |
+| Problem Functions | OrderSelect(), MarketInfo(), Bid, Digits, Point |
+| Trigger | MetaEditor hung while processing errors |
+| Wine Factor | Windows apps in Wine are less stable with errors |
+
+### What Happened:
+1. MetaEditor tried to compile OrdersEA.mq5
+2. Found 100 MT4-specific syntax errors
+3. Got stuck in error processing loop
+4. VNC session froze (MetaEditor was active window)
+5. Required container restart to clear
+
+### Solutions Implemented:
+
+**1. Syntax Checker** (`check-syntax.sh`)
+```bash
+./check-syntax.sh OrdersEA.mq5
+# Detects MT4 functions before compilation
+```
+
+**2. Watchdog** (`metaeditor-watchdog.sh`)
+- Auto-kills MetaEditor if running >5 minutes
+- Kills if CPU >50% for extended period
+
+**3. Safe Compile** (`safe-compile.sh`)
+- 2-minute timeout on compilations
+- Auto-kills on timeout
+- Prevents indefinite hangs
+
+### Prevention Tips:
+1. Always check syntax before compiling unknown files
+2. Use MT4→MT5 conversion tools for old code
+3. Watch for MetaEditor freezes during compilation
+4. Restart container if VNC becomes unresponsive