v1.8.90: fix update script — remove $ErrorActionPreference=Stop, launch via cmd start

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

core/updater.py

@@ -272,24 +272,23 @@ class UpdateChecker:
             exe_dir = os.path.dirname(current_exe)
 
             ps_content = f"""
-$ErrorActionPreference = 'Stop'
 $pid = {pid}
 $src = '{new_exe}'
 $dst = '{current_exe}'
-$mei = '{mei_dir}'
-$exeDir = '{exe_dir}'
 $tempDir = '{tmp_dir}'
 
 # Wait for old process to exit
 while (Get-Process -Id $pid -ErrorAction SilentlyContinue) {{
     Start-Sleep -Seconds 1
 }}
-Start-Sleep -Seconds 2
+Start-Sleep -Seconds 3
 
-# Clean ALL stale _MEI directories (PyInstaller temp dirs)
-Get-ChildItem -Path $tempDir -Directory -Filter '_MEI*' -ErrorAction SilentlyContinue | ForEach-Object {{
-    Remove-Item -Path $_.FullName -Recurse -Force -ErrorAction SilentlyContinue
-}}
+# Clean ALL stale _MEI directories (best-effort, skip locked)
+try {{
+    Get-ChildItem -Path $tempDir -Directory -Filter '_MEI*' -ErrorAction SilentlyContinue | ForEach-Object {{
+        Remove-Item -Path $_.FullName -Recurse -Force -ErrorAction SilentlyContinue
+    }}
+}} catch {{}}
 Start-Sleep -Seconds 1
 
 # Copy with retry
@@ -311,8 +310,8 @@ if (-not $copied) {{ exit 1 }}
 
 Start-Sleep -Seconds 2
 
-# Launch new exe via explorer.exe (mimics user double-click, clean environment)
-Start-Process explorer.exe $dst
+# Launch new exe via cmd start (clean environment, proper path handling)
+Start-Process cmd.exe -ArgumentList '/c', 'start', '""', ('"{0}"' -f $dst) -WindowStyle Hidden
 
 # Cleanup
 Start-Sleep -Seconds 3