fix(menu): preview current update selection

TODO.md

@@ -17,7 +17,7 @@
 - [ ] Keep shared MCPorter servers until neither client needs them. Reconciliation processes `shared` records even when only one client is selected; uninstalling that client with an empty selection removes servers still used by the other. (`scripts/lib/managed-extensions.py:463`, `scripts/commands/uninstall.ps1:59`, `scripts/commands/uninstall.sh:77`)
 - [ ] Manage global packages once across clients. With `--client both`, MCPorter is installed and recorded twice; QMD's global package can be removed during a Codex-only deselection while Claude still uses its plugin. (`scripts/lib/managed-extensions.py:342`, `scripts/lib/managed-extensions.py:378`, `scripts/lib/managed-extensions.py:463`)
 - [x] Fix Bash `auto` semantic retrieval selection. Both `test_semantic_retrieval_device()` and its caller read `$?` after a completed `if`, losing the benchmark's exit code; an unsuitable device produces an empty choice instead of `false`. (`scripts/lib/semantic-retrieval.sh:13`, `scripts/lib/install-options.sh:52`)
-- [ ] Make ordinary update dry-runs use the saved/current selection. Both menus bypass selection in dry-run and select every manifest entry, so the preview can diverge from the real update. (`scripts/lib/plugins.ps1:91`, `scripts/lib/plugins.sh:97`)
+- [x] Make ordinary update dry-runs use the saved/current selection. Both menus bypass selection in dry-run and select every manifest entry, so the preview can diverge from the real update. (`scripts/lib/plugins.ps1:91`, `scripts/lib/plugins.sh:97`)
 - [ ] Reconcile resources whose ownership record remains but whose installation was removed manually. `ensure_cli()` and `ensure_mcporter()` return early from a ledger record without checking the actual CLI or server; normal sync cannot restore the missing resource. (`scripts/lib/managed-extensions.py:342`, `scripts/lib/managed-extensions.py:395`)
 - [ ] Update owned MCPorter itself on `--update`. `ensure_cli()` returns whenever its ledger record exists, so a selected MCPorter package never receives the requested update. (`scripts/lib/managed-extensions.py:342`)
 - [x] Keep terminal newlines in Bash-managed files that need substitution. Command substitution strips trailing newlines before Bash hashes and writes the content, while PowerShell retains them; switching installers causes needless file changes and backups. (`scripts/lib/manifest.sh:70`, `scripts/lib/manifest.ps1:75`)

scripts/lib/plugins.ps1

@@ -92,7 +92,7 @@ function Select-ConfiguredPlugins {
     $entries = @(Get-ConfiguredPluginEntries -RepositoryRoot $RepositoryRoot)
     $toggleable = @($entries)
     $fixed = @($entries | Where-Object { $toggleable -notcontains $_ })
-    if ($DryRun -or $toggleable.Count -eq 0) { return @{ Selected = $entries; Deselected = @() } }
+    if ($toggleable.Count -eq 0 -or ($DryRun -and $Mode -eq 'Install')) { return @{ Selected = $entries; Deselected = @() } }
 
     $referenceClients = if ($Client -eq 'Both') { @('Claude','Codex') } else { @($Client) }
     $installed = @{}
@@ -116,7 +116,7 @@ function Select-ConfiguredPlugins {
         $found
     })
     $names = @($toggleable | ForEach-Object { $_.name })
-    $checked = Read-PluginToggleSelection -Names $names -Checked $checked
+    if (-not $DryRun) { $checked = Read-PluginToggleSelection -Names $names -Checked $checked }
 
     $selected = @()
     $deselected = @()

scripts/lib/plugins.sh

@@ -107,7 +107,7 @@ select_configured_plugins() {
     if plugin_toggleable "$root" "$name" "$client"; then toggle_names+=("$name"); else fixed_names+=("$name"); fi
   done < <(get_plugin_names "$root")
 
-  if [ "$dry_run" = true ] || [ ${#toggle_names[@]} -eq 0 ]; then
+  if [ ${#toggle_names[@]} -eq 0 ] || { [ "$dry_run" = true ] && [ "$mode" = Install ]; }; then
     selected_ref=("${all_names[@]}")
     return 0
   fi
@@ -144,7 +144,7 @@ select_configured_plugins() {
     checked+=("$found")
   done
 
-  read_plugin_toggle_selection toggle_names checked
+  if [ "$dry_run" != true ]; then read_plugin_toggle_selection toggle_names checked; fi
 
   local i
   for ((i = 0; i < ${#toggle_names[@]}; i++)); do