[6.x] Restore field action menus and handles in the new form system

[brianjhanson]

BaseField::formNode() never called ->actions(), so the "⋮" menu every field carried in Craft 5 — Field settings, Copy field handle — was absent from every form the new system renders, along with the inline handle chip admins see with the "Show field handles in edit forms" preference on.

Everything feeding that menu survived the port but had no caller: actionMenuItems(), copyAttributeAction(), showAttribute(), the six native field overrides, and FieldLayoutActionMenuItemsResolving (whose yii2-adapter bridge to DefineFieldActionsEvent was already wired and waiting). The inputHtml() tier was orphaned too, which left copyAttributeAction() with no live call sites at all.

Adds craft:action-menu and craft:copy-attribute Form Nodes, emitted from formNode() into the Field node's existing actions slot. Node UIDs derive from the control path, not the layout element UID: that UID is nullable, and one layout element can emit several Fields (LatLongField).

Item behavior is now declarative. HtmlStack::jsWithVars registers JS on a full page load only, so a menu built that way is inert on exactly the Inertia-rendered screens this targets. Items instead carry BaseAction descriptors that craft-action-item runs, with listeners in resources/js/modules/fields. Matrix's expand/collapse-all and the Matrix and Addresses copy-all items are converted the same way; their listeners scope to the invoking item's own craft-field, preserving the direct-descendant scoping the old jQuery selectors relied on, which the two render paths spell differently.

ElementHtml's three private action-menu rendering methods move to a shared Cp\Components\ActionMenu. Both renderers now consume one canonical item shape, so the HTML and Vue paths can't drift.

Two known gaps: the old handlers hid or disabled items on menu open (expand-all only when something was collapsed, copy greyed out when empty), which isn't reproduced; and "Copy value from site…" is still absent, since it needs a values key on CopyElementValuesController's response, a Vue site picker, and a listener that calls setValue() — the legacy modal resolves its field through .closest('.menu').data('disclosureMenu').

Description

Related issues

[github-actions]

📚 Storybook previews

@craftcms/ui — open Storybook

No changed components detected in this Storybook.

resources/js — open Storybook

No changed components detected in this Storybook.