feat(retrieval): offer device benchmark

scripts/lib/semantic-retrieval.ps1

@@ -8,3 +8,11 @@ function Sync-SemanticRetrieval {
     & python @arguments
     if ($LASTEXITCODE -ne 0) { throw 'Semantic retrieval reconciliation failed.' }
 }
+
+function Test-SemanticRetrievalDevice {
+    param([Parameter(Mandatory=$true)][string]$RepositoryRoot,[Parameter(Mandatory=$true)][string]$HomePath,[switch]$Summary)
+    & python (Join-Path $PSScriptRoot 'semantic-retrieval.py') benchmark --root $RepositoryRoot --home $HomePath $(if ($Summary) { '--summary' }) | Write-Host
+    if ($LASTEXITCODE -eq 0) { return $true }
+    if ($LASTEXITCODE -eq 2) { return $false }
+    throw 'Semantic retrieval benchmark failed.'
+}