Runs one structural operation on this project's page assignments, selected by op. All operations are live writes (routing changes immediately, no draft or publish step).

Operations:

• update (content:write): changes handle and locale of 1-100 assignments by id. Every id must belong to this project; one foreign id refuses the whole batch with 404 and nothing moves. Returns the updated rows. A handle that another assignment already uses in that scope, or a custom page that would hold two handles in one scope (details.handles), returns 409 CONFLICT and nothing moves.
• localize (content:write): creates a locale-specific copy of page pageId for locale, with the same type and handle and a copy of its SEO. Returns the new page.
• unassign (content:delete, confirm equal to pageId): removes up to 100 resource assignments (assignmentIds) from template page pageId. Only rows that template owns in this project are removed; other ids are ignored. The template's own wiring row and the page itself are never removed. Returns the number removed.
• reset-localized (content:delete, confirm equal to assignmentId): removes the localized assignment assignmentId of page pageId so the route falls back to the default page. A version of the content is kept for recovery.
• rename-locale (content:delete, confirm equal to the projectId): moves every assignment of the project from fromLocale to toLocale. Returns the number of rows moved.

A wrong confirm value returns 400 INVALID_PARAMS.

Required scope: content:write (all operations); unassign, reset-localized and rename-locale also need content:delete