feat(12.1-01): declared bulk actions on admin lists

- pact.HasAdminBulkActions with AdminBulkAction, its input and result
- config_list.yaml bulkActions, compiled fail-loud, needs showCheckboxes
- POST .../{controller}/bulk/{action}: ids resolved and locked through the
  list scope in one transaction; partial selection is 409
- list schema offers declared actions per principal, with confirm text
- admin SPA bulk actions menu with confirm, busy state and failure toasts
- acme.roster fixture, tracer test, OpenAPI, TS types, dist, READMEs, docs

modules/pact/capabilities.go

@@ -255,6 +255,50 @@ type HasAdminActions interface {
 	AdminActions() []AdminAction
 }
 
+// AdminBulkAction is one controller action an administrator runs on the rows
+// selected in a list (config_list.yaml bulkActions). The admin framework owns
+// the HTTP route, the CSRF check, authentication, the resolution of the posted
+// ids and the transaction; Run only carries the business logic and reads the
+// write transaction with cabana.TxFromContext. Name is an identifier unique
+// among the controller's bulk actions; create and delete are reserved, and a
+// record action may reuse a bulk action's name. Label and Confirm are phrase
+// keys or literal text: Label is the menu item, Confirm the confirmation
+// question, and an empty Confirm means the framework's default confirm text.
+// Permissions are checked in addition to the controller's
+// RequiredPermissions.
+type AdminBulkAction struct {
+	Name        string
+	Label       string
+	Confirm     string
+	Permissions []string
+	Run         func(ctx context.Context, in AdminBulkActionInput) (AdminBulkActionResult, error) `json:"-"`
+}
+
+// AdminBulkActionInput is what the framework hands an AdminBulkAction.
+// Records are pointers to the controller's model, loaded and row-locked
+// through the controller's ListExtendQuery scope and ordered by primary key.
+// A bulk action never receives ids, so an id list can never become an
+// unscoped lookup.
+type AdminBulkActionInput struct {
+	Records []any
+}
+
+// AdminBulkActionResult is a bulk action's answer. Message is a phrase key or
+// text, localized by the framework and shown as a toast; when it is empty the
+// admin shows its default text with Affected. Affected is the number of
+// records the action changed, which may be lower than the selection when the
+// action skips rows.
+type AdminBulkActionResult struct {
+	Message  string
+	Affected int
+}
+
+// HasAdminBulkActions is implemented by an admin controller that registers
+// named bulk actions for its config_list.yaml bulkActions list.
+type HasAdminBulkActions interface {
+	AdminBulkActions() []AdminBulkAction
+}
+
 // AdminPartialData supplies the view model a controller partial template
 // renders (config_list.yaml headerPartial, fields.yaml `type: partial`). name
 // is the partial name; record is the scoped record for a form partial on an