fix: apply all FIX-TODO items (P0/P1/P2)

P0 bugs:
- Invoke-CIJob.ps1: skip --depth 1 when $Commit specified (shallow clone
  + checkout specific commit was silently failing)
- Get-BuildArtifacts.ps1: check .Length -eq 0 not rounded sizeKB (false
  fail on artifacts smaller than 50 bytes)
- build-nsis.yml: upgrade upload-artifact v3 -> v4 (v3 deprecated)

P0 security:
- Remove hardcoded default password CIBuild!ChangeMe2026 from all scripts,
  README, TODO; prompt Read-Host -AsSecureString at runtime instead
- Setup-TemplateVM.ps1: replace `net user $u $p /add` (password in argv /
  audit log 4688) with New-LocalUser + local ConvertTo-SecureString
- Prepare-TemplateSetup.ps1: save and restore WSMan AllowUnencrypted +
  TrustedHosts in finally block (was permanently mutating host WinRM config)
- Setup-TemplateVM.ps1: remove duplicate MaxMemoryPerShellMB (winrm set
  + Set-Item both setting same value)

P1 doc (stale Host-Only / VMnet11 era):
- Setup-TemplateVM.ps1: rewrite NETWORK REQUIREMENT block + final steps
  (system uses VMnet8 NAT permanently, not VMnet11 Host-Only)
- Invoke-CIJob.ps1 Phase 1 comment: correct network model
- ARCHITECTURE.md: remove Git from toolchain list (not installed); clarify
  zip-transfer rationale (no PAT in VM, not network isolation)
- BEST-PRACTICES.md: rewrite Step 8 as NAT topology verification

P1 minor:
- Invoke-RemoteBuild.ps1: remove wasted first New-Item (created then
  immediately removed and recreated)
- Wait-VMReady.ps1: remove unused $elapsed; simplify try/catch around
  native command (exit codes don't throw)
- Install-Runner.ps1: add deprecation notice pointing to Setup-Host.ps1

P2 operational:
- Add scripts/Cleanup-OrphanedBuildVMs.ps1 with -WhatIf support
- Get-BuildArtifacts.ps1 -IncludeLogs: add -Recurse (msbuild logs in subdir)
- Add gitea/workflows/lint.yml (PSScriptAnalyzer on .ps1 push/PR)

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

template/Prepare-TemplateSetup.ps1

@@ -24,9 +24,9 @@
       1. Shut down the VM
       2. Take snapshot: VM → Snapshot → Take Snapshot → name: BaseClean
          (VM stays on VMnet8 NAT — internet access is required for builds)
-      3. Store credentials on host:
+      3. Store credentials on host (use the same password chosen during provisioning):
          New-StoredCredential -Target 'BuildVMGuest' -UserName 'ci_build' `
-             -Password 'CIBuild!ChangeMe2026' -Persist LocalMachine
+             -Password '<your-build-password>' -Persist LocalMachine
 
 .PARAMETER VMIPAddress
     IP address of the template VM while it is on NAT (VMnet8).
@@ -69,7 +69,7 @@ param(
 
     [string] $AdminPassword = '',
 
-    [string] $BuildPassword = 'CIBuild!ChangeMe2026',
+    [string] $BuildPassword = '',
 
     [string] $DotNetSdkVersion = '10.0',
 
@@ -81,6 +81,15 @@ $ErrorActionPreference = 'Stop'
 
 $scriptDir = Split-Path -Parent $MyInvocation.MyCommand.Path
 
+# Prompt for BuildPassword if not supplied — never use a hardcoded default.
+if ($BuildPassword -eq '') {
+    Write-Host "[Prepare] No -BuildPassword supplied. Enter password for the CI build account inside the VM:"
+    $secPwd      = Read-Host -Prompt "  BuildPassword" -AsSecureString
+    $bstr        = [System.Runtime.InteropServices.Marshal]::SecureStringToBSTR($secPwd)
+    $BuildPassword = [System.Runtime.InteropServices.Marshal]::PtrToStringAuto($bstr)
+    [System.Runtime.InteropServices.Marshal]::ZeroFreeBSTR($bstr)
+}
+
 # ── Build PSCredential ────────────────────────────────────────────────────────
 if ($AdminPassword -eq '') {
     Write-Host "[Prepare] Enter administrator credentials for the template VM ($VMIPAddress):"
@@ -94,15 +103,19 @@ else {
 $sessionOptions = New-PSSessionOption -SkipCACheck -SkipCNCheck -SkipRevocationCheck
 
 # ── Configure HOST-side WinRM client (required for Basic auth over HTTP) ──────
-# These settings apply to this machine (the host), not the VM.
-# AllowUnencrypted is needed for HTTP/5985 Basic auth in a lab environment.
-Write-Host "[Prepare] Configuring host WinRM client for unencrypted Basic auth..."
+# AllowUnencrypted is needed for HTTP/5985 Basic auth. We save the prior value
+# and restore it in the finally block so this script doesn't permanently change
+# the host security posture.
+Write-Host "[Prepare] Configuring host WinRM client for unencrypted Basic auth (will be restored on exit)..."
+$prevAllowUnencrypted = $null
+$prevTrustedHosts     = $null
 try {
+    $prevAllowUnencrypted = (Get-Item WSMan:\localhost\Client\AllowUnencrypted -ErrorAction Stop).Value
+    $prevTrustedHosts     = (Get-Item WSMan:\localhost\Client\TrustedHosts     -ErrorAction Stop).Value
     Set-Item WSMan:\localhost\Client\AllowUnencrypted $true -Force -ErrorAction Stop
     # Add VM IP to TrustedHosts if not already present
-    $currentTrusted = (Get-Item WSMan:\localhost\Client\TrustedHosts).Value
-    if ($currentTrusted -ne '*' -and $currentTrusted -notlike "*$VMIPAddress*") {
-        $newTrusted = if ($currentTrusted -eq '') { $VMIPAddress } else { "$currentTrusted,$VMIPAddress" }
+    if ($prevTrustedHosts -ne '*' -and $prevTrustedHosts -notlike "*$VMIPAddress*") {
+        $newTrusted = if ($prevTrustedHosts -eq '') { $VMIPAddress } else { "$prevTrustedHosts,$VMIPAddress" }
         Set-Item WSMan:\localhost\Client\TrustedHosts -Value $newTrusted -Force -ErrorAction Stop
     }
     Write-Host "[Prepare] Host WinRM client configured."
@@ -230,7 +243,7 @@ try {
     Write-Host " 3. Store CI credentials on this HOST:"
     Write-Host "    (run in elevated PowerShell with CredentialManager module)"
     Write-Host "    New-StoredCredential -Target 'BuildVMGuest' ``"
-    Write-Host "        -UserName 'ci_build' -Password '$BuildPassword' ``"
+    Write-Host "        -UserName 'ci_build' -Password '<your-build-password>' ``"
     Write-Host "        -Persist LocalMachine"
     Write-Host ""
     Write-Host " 4. Verify runner online in Gitea: http://10.10.20.11:3100"
@@ -239,4 +252,13 @@ try {
 }
 finally {
     Remove-PSSession $session -ErrorAction SilentlyContinue
+
+    # Restore host WinRM client settings to their original values
+    if ($null -ne $prevAllowUnencrypted) {
+        Set-Item WSMan:\localhost\Client\AllowUnencrypted $prevAllowUnencrypted -Force -ErrorAction SilentlyContinue
+    }
+    if ($null -ne $prevTrustedHosts) {
+        Set-Item WSMan:\localhost\Client\TrustedHosts -Value $prevTrustedHosts -Force -ErrorAction SilentlyContinue
+    }
+    Write-Host "[Prepare] Host WinRM client settings restored."
 }