docker isolation (new) + default agent type (moved) in config wizard

libs/mngr/changelog/ev-install-set-isolate.md

@@ -0,0 +1,9 @@
+`mngr config wizard` now covers two more common user-scope settings.
+
+- Docker host-volume isolation: the wizard asks whether each docker host should see only its own `host_dir` sub-folder (the recommended, forthcoming default; requires Docker Engine >= 25.0) or keep the legacy shared state volume, writing `providers.docker.isolate_host_volumes`. Opting in silences the one-shot deprecation warning that a fresh install otherwise hits the first time it uses docker.
+
+- Default agent type: the "pick a default agent type for `mngr create`" step moved here from `mngr extras`. Because the wizard runs as its own step in the installer (after plugins are installed), it now sees freshly-installed plugin agent types instead of only those registered at startup.
+
+Every prompt now includes an explicit "leave unset for now" option, so you can defer a choice instead of having to pick a value or cancel.
+
+Each step short-circuits when its setting is already configured, so re-running the wizard only fills gaps. The "already configured?" check reads every config scope (user, project, and local), so a value set in any of them suppresses the prompt. `mngr extras` no longer has a `config` subcommand or a default-agent-type step; user-scope config setup lives entirely in `mngr config wizard`.

libs/mngr/docs/commands/secondary/config.md

@@ -538,10 +538,16 @@ configured, so re-running only prompts for what is still unset. Run
 automatically by the installer.
 
 Steps:
+  Default agent type           The default agent type for `mngr create`
+                               (skipped when no agent types are registered yet).
   Claude config dir isolation  Whether each local Claude agent gets its own
                                config dir (mngr leaves your default Claude
                                config untouched) or shares your default config
                                (needed for Claude subscriptions on macOS).
+  Docker host-volume isolation Whether each docker host sees only its own
+                               host_dir sub-folder (the recommended, forthcoming
+                               default; requires Docker Engine >= 25.0) or shares
+                               one state volume.
 
 **Usage:**