feat: complete production workflow migration

deploy/windows-service/uninstall.ps1

@@ -0,0 +1,20 @@
+# Legacy Windows compatibility only. This removes the NSSM process supervisor;
+# project data, browser state, and Python scheduler state are preserved.
+param(
+    [string]$ServiceName = "gyxx-flow-scheduler",
+    [string]$NssmPath = "nssm.exe"
+)
+
+$ErrorActionPreference = "Stop"
+Set-StrictMode -Version Latest
+$nssm = (Get-Command $NssmPath -ErrorAction Stop).Source
+
+& $nssm stop $ServiceName
+if ($LASTEXITCODE -notin @(0, 3)) {
+    throw "Unable to stop service $ServiceName (exit code $LASTEXITCODE)"
+}
+& $nssm remove $ServiceName confirm
+if ($LASTEXITCODE -ne 0) {
+    throw "Unable to remove service $ServiceName (exit code $LASTEXITCODE)"
+}
+Write-Host "Service removed. Project data and scheduler state were preserved."