fix sync bug for scheduled work

scheduling/Register-AiChatSyncTask.ps1

@@ -50,9 +50,15 @@ if (-not (Test-Path $launcher)) {
 # Task Scheduler runs multiple actions in order but reports only the last one's
 # result, so a failure in an earlier provider would be invisible. The loop keeps
 # going after a failure and propagates a non-zero exit code.
+#
+# /v:on and !RC! are required, not stylistic: cmd expands every %VAR% on a
+# command line *before* running any of it, so "exit /b %RC%" would report the
+# value RC had before the loop ever ran - i.e. always success. Delayed expansion
+# reads it at the point of use.
 $loop = ($Provider | ForEach-Object { "`"$launcher`" sync --provider $_ --joplin-optional || set RC=1" }) -join ' & '
+$taskArgs = "/v:on /c set RC=0 & $loop & exit /b !RC!"
 $actions = New-ScheduledTaskAction -Execute 'cmd.exe' `
-    -Argument "/c set RC=0 & $loop & exit /b %RC%" `
+    -Argument $taskArgs `
     -WorkingDirectory $repo
 
 $trigger = New-ScheduledTaskTrigger -Daily -At $Time
@@ -75,6 +81,10 @@ Register-ScheduledTask -TaskName $TaskName `
 
 Write-Host "Registered '$TaskName' - daily at $Time for: $($Provider -join ', ')"
 Write-Host ''
+Write-Host 'Command the task will run:'
+Write-Host "  cmd.exe $taskArgs"
+Write-Host "  (working directory: $repo)"
+Write-Host ''
 Write-Host 'Next steps:'
 Write-Host "  * Run it once now:      Start-ScheduledTask -TaskName $TaskName"
 Write-Host "  * Check the result:     Get-ScheduledTaskInfo -TaskName $TaskName"