Make Local Agent desktop dashboard single-instance

app/modules/documents/local_agent_runtime/open_dashboard.bat

@@ -1,3 +1,16 @@
 @echo off
+setlocal
 cd /d "%~dp0"
-wscript.exe "%~dp0Open ERP Local Agent Dashboard.vbs"
+
+if not exist ".venv\Scripts\pythonw.exe" (
+    echo ERROR: ERP Local Agent Python environment was not found.
+    exit /b 1
+)
+
+if not exist "ERPAgentDashboard.pyw" (
+    echo ERROR: ERPAgentDashboard.pyw was not found.
+    exit /b 1
+)
+
+start "" ".venv\Scripts\pythonw.exe" "ERPAgentDashboard.pyw"
+exit /b 0