Package portable grid agent operation (#134)

packaging/metacrate-grid-agent/install.ps1

@@ -0,0 +1,15 @@
+param(
+    [Parameter(Mandatory = $true)][string]$BuiltBinary,
+    [Parameter(Mandatory = $true)][string]$DestinationDirectory
+)
+$ErrorActionPreference = "Stop"
+if (-not (Test-Path -LiteralPath $BuiltBinary -PathType Leaf)) {
+    throw "BuiltBinary is not a regular file"
+}
+New-Item -ItemType Directory -Force -Path $DestinationDirectory | Out-Null
+$temporary = Join-Path $DestinationDirectory ".metacrate-grid-agent.new.exe"
+Copy-Item -LiteralPath $BuiltBinary -Destination $temporary -Force
+Move-Item -LiteralPath $temporary -Destination (Join-Path $DestinationDirectory "metacrate-grid-agent.exe") -Force
+
+# Configuration, secrets, conversations, landmarks, and journals live outside
+# this directory and are deliberately never created, replaced, or removed.