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>

gitea/workflows/lint.yml

@@ -0,0 +1,55 @@
+# PSScriptAnalyzer lint — runs on every push/PR that touches PowerShell files.
+# Requires PSScriptAnalyzer installed on the runner host:
+#   Install-Module PSScriptAnalyzer -Scope AllUsers -Force
+#
+# Failures block the PR. Fix warnings with:
+#   Invoke-ScriptAnalyzer -Path scripts\ -Recurse -Fix
+
+name: Lint (PSScriptAnalyzer)
+
+on:
+  push:
+    paths:
+      - '**.ps1'
+      - '**.psm1'
+  pull_request:
+    paths:
+      - '**.ps1'
+      - '**.psm1'
+
+jobs:
+  lint:
+    runs-on: windows-build
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Run PSScriptAnalyzer
+        shell: pwsh
+        run: |
+          $ErrorActionPreference = 'Stop'
+
+          if (-not (Get-Module -ListAvailable PSScriptAnalyzer)) {
+            Write-Host "Installing PSScriptAnalyzer..."
+            Install-Module PSScriptAnalyzer -Scope CurrentUser -Force -AllowClobber
+          }
+
+          $paths = @('scripts', 'template', 'runner', 'Setup-Host.ps1')
+          $results = $paths | ForEach-Object {
+            if (Test-Path $_) {
+              Invoke-ScriptAnalyzer -Path $_ -Recurse -Severity Error,Warning
+            }
+          }
+
+          if ($results) {
+            $results | Format-Table -AutoSize
+            Write-Error "PSScriptAnalyzer found $($results.Count) issue(s). Fix before merging."
+            exit 1
+          }
+          else {
+            Write-Host "PSScriptAnalyzer: no issues found."
+          }