Document that content_type template wires parent allowed_content_types itself

Containment is handled by the template's post-copy hook; the agent
should pass global_allow=false + parent_content_type and not hand-edit
parent FTI types/*.xml.

Author: MrTango

plonecli/skills/plonecli/reference/add.md

@@ -44,7 +44,7 @@ Always confirm what is actually available here with `plonecli -l` (run inside th
 
 | Subtemplate | Adds | Typical follow-up |
 |---|---|---|
-| `content_type` | A Dexterity content type (schema, FTI, registration). | Add schema fields ([fields.md](fields.md)); restart/reinstall so the new type is registered; add tests. |
+| `content_type` | A Dexterity content type (schema, FTI, registration). For containment, also wires the new type into the parent's `allowed_content_types`. | Add schema fields ([fields.md](fields.md)); restart/reinstall so the new type is registered; add tests. |
 | `behavior` | A behavior (reusable schema/marker applied to content types). | Add schema fields ([fields.md](fields.md)); wire the behavior onto a content type; add tests. |
 | `restapi_service` | A `plone.restapi` service (endpoint, adapter, registration). | Add tests exercising the endpoint. |
 

plonecli/skills/plonecli/reference/templates.md

@@ -118,6 +118,13 @@ Example: `plonecli add behavior --defaults -d behavior_name="IFeatured"`
 Hidden/computed: `content_type_class`, `content_type_module`, `content_type_interface`,
 `content_type_portal_type`, `parent_content_type_resolved`.
 
+**Containment is fully wired by the template — do not edit the parent FTI yourself.** When you
+pass `global_allow=false` + `parent_content_type`, the post-copy hook adds the new type to that
+parent's `allowed_content_types`: it edits the parent FTI's `types/*.xml` if the parent lives in
+this package, or creates a minimal `purge="False"` FTI override (e.g. for stock Plone `Folder`) that
+only appends the new type. So just answer `parent_content_type` (and `parent_content_type_manual`
+for a type not in the choices) — never hand-edit allowed types in any `types/*.xml` before or after.
+
 Example (containment): `plonecli add content_type --defaults -d content_type_name="Talk" -d global_allow=false -d parent_content_type="Folder"`
 
 ### `restapi_service` — `plone.restapi` endpoint