Add audited, versioned MCP save workflow (#1452)

- `--export ... --target-version`, and explicit target_format /
  target_version on automation and protocol saves; a conversion that
  would drop unsupported records is refused unless allow_lossy is set.
- `audit` read op: dangling layers/blocks, duplicate handles, non-finite
  bounds, serialization, lossy records and the source DXF handle graph.
- `save_verified`: writes the requested version from the same snapshot a
  normal save writes, reopens it, checks the version and the entity
  manifest, audits the ASCII DXF handle graph and returns a SHA-256.
- ZOOM EXTENTS includes SDF text glyphs.
- Live MCP acceptance script and an optional reference-console audit
  runner under docs/automation.

Squashed from the PR with review fixes: merged with the DWT save path,
the save snapshot, the tool lists added since, and vendor-neutral
harness names; the dated verification record is left out.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/automation/reference_acceptance.ps1

@@ -0,0 +1,67 @@
+param(
+    [Parameter(Mandatory = $true)]
+    [string]$Directory,
+    [Parameter(Mandatory = $true)]
+    [string]$ConsolePath,
+    [int]$TimeoutSeconds = 25
+)
+
+$ErrorActionPreference = 'Stop'
+$drawingDirectory = (Resolve-Path -LiteralPath $Directory).Path
+$scriptPath = Join-Path $PSScriptRoot 'reference_audit.scr'
+$targets = @(
+    @{ Version = '2000'; File = 'mcp-acceptance-2000.dwg' },
+    @{ Version = '2013'; File = 'mcp-acceptance-2013.dwg' },
+    @{ Version = '2018'; File = 'mcp-acceptance-2018.dwg' }
+)
+$results = foreach ($target in $targets) {
+    $drawing = Join-Path $drawingDirectory $target.File
+    if (-not (Test-Path -LiteralPath $drawing -PathType Leaf)) {
+        throw "Missing acceptance drawing: $drawing"
+    }
+    $isolation = Join-Path $env:TEMP "ocs-reference-acceptance-$($target.Version)"
+    New-Item -ItemType Directory -Force -Path $isolation | Out-Null
+
+    $start = [Diagnostics.ProcessStartInfo]::new()
+    $start.FileName = $ConsolePath
+    $start.UseShellExecute = $false
+    $start.CreateNoWindow = $true
+    $start.RedirectStandardOutput = $true
+    $start.RedirectStandardError = $true
+    $start.StandardOutputEncoding = [Text.Encoding]::Unicode
+    $start.StandardErrorEncoding = [Text.Encoding]::Unicode
+    @(
+        '/i', $drawing,
+        '/s', $scriptPath,
+        '/l', 'en-US',
+        '/isolate', "ocsaccept$($target.Version)", $isolation,
+        '/readonly'
+    ) | ForEach-Object { [void]$start.ArgumentList.Add($_) }
+
+    $process = [Diagnostics.Process]::new()
+    $process.StartInfo = $start
+    [void]$process.Start()
+    $stdout = $process.StandardOutput.ReadToEndAsync()
+    $stderr = $process.StandardError.ReadToEndAsync()
+    $forcedTermination = -not $process.WaitForExit($TimeoutSeconds * 1000)
+    if ($forcedTermination) {
+        $process.Kill($true)
+        $process.WaitForExit()
+    }
+    $text = $stdout.Result + $stderr.Result
+    $log = Join-Path $drawingDirectory "reference-audit-$($target.Version).log"
+    [IO.File]::WriteAllText($log, $text, [Text.UTF8Encoding]::new($false))
+    $passed = [regex]::IsMatch($text, 'Total errors found\s+0\s+fixed\s+0')
+    [pscustomobject]@{
+        Version = $target.Version
+        Passed = $passed
+        ForcedTermination = $forcedTermination
+        ExitCode = $process.ExitCode
+        Log = $log
+    }
+}
+
+$results | Format-Table -AutoSize
+if ($results.Passed -contains $false) {
+    exit 1
+}