#3079 Docs: remove followUpActions from the MethodResult reference in the extension model manual

What changed

swamp-club#3078 removes the followUpActions feature from swamp. It has had no producer since February 2026, and extension methods could never produce it: the extension method wrapper (wrapUserExecute in src/domain/extensions/model_kind_adapter.ts) returns only dataHandles, so a returned followUpActions value was silently discarded.

Which manual page needs updating

content/manual/reference/extensions/model.md in swamp-club/swamp-club, the MethodResult table (around line 286), currently lists:

| followUpActions | FollowUpAction[] | No | Actions to execute after the method returns. |

Suggested change

• Delete the followUpActions row, leaving dataHandles as the only MethodResult field.
• Remove any FollowUpAction type description on the same page if one exists.
• No replacement text is needed; the field never worked for extension authors, so there is no migration to describe.

Found during triage of swamp-club#3078.