refactor(deploy): stream shell scripts over SSH and support binary-only updates

scripts/tests/ssh_stdin.ps1

@@ -0,0 +1,34 @@
+#!/usr/bin/env pwsh
+# Run with pwsh -NoProfile -File scripts/tests/ssh_stdin.ps1 on Linux/WSL.
+$ErrorActionPreference = 'Stop'
+. "$PSScriptRoot/../lib.ps1"
+
+# Exercise the real native-command pipeline without contacting a server.
+$body = "printf '%s\n' `"owner's directory`"`nprintf '%s\n' 'second line'"
+$output = @(Invoke-Ext -Exe sh -Arguments @('-s') -Label test -Stdin $body)
+if (($output -join '|') -cne "owner's directory|second line") { throw 'stdin script changed in transit' }
+$output = @(Invoke-Ext -Exe sh -Arguments @('-c', 'printf command-only') -Label test)
+if (($output -join '') -cne 'command-only') { throw 'Command-only execution changed' }
+$failed = $false
+try { Invoke-Ext -Exe sh -Arguments @('-s') -Label test -Stdin 'exit 7' } catch { $failed = $true }
+if (-not $failed) { throw 'stdin execution swallowed a failure' }
+
+# Test SSH argument and stdin forwarding independently of native SSH availability.
+function Test-IsWsl { return $true }
+function Get-SshpassCommand { return $script:Sshpass }
+function Invoke-Ext {
+    param($Exe, $Arguments, $Label, [string]$Stdin)
+    $script:Call = @{ Exe = $Exe; Arguments = $Arguments; Stdin = $Stdin; HasStdin = $PSBoundParameters.ContainsKey('Stdin') }
+}
+$script:Sshpass = $null
+Invoke-Ssh -Cmd 'sh -s' -User root -Remote test -Stdin "printf ok`r`n"
+if ($script:Call.Exe -ne 'ssh' -or $script:Call.Stdin.Contains("`r") -or -not $script:Call.HasStdin) {
+    throw 'SSH stdin was not normalized and forwarded'
+}
+if (($script:Call.Arguments[-2..-1] -join '|') -ne 'root@test|sh -s') { throw 'SSH command changed' }
+Invoke-Ssh -Cmd 'true' -User root -Remote test
+if ($script:Call.HasStdin) { throw 'Command-only SSH unexpectedly redirects stdin' }
+$script:Sshpass = '/fake/sshpass'
+Invoke-Ssh -Cmd 'sh -s' -User root -Remote test -Pass test-only -Stdin $body
+if ($script:Call.Exe -ne '/fake/sshpass' -or $script:Call.Stdin -cne $body) { throw 'sshpass lost stdin' }
+Write-Host 'SSH stdin tests passed'