ATTDEF dialog error band and multi-line editor; ATTDISP sets ATTMODE

Validation messages show in the dialogs, the Default value of a multi-line
definition can be edited in the multi-line text editor, "Specify on-screen"
is kept for the session, ATTDISP sets ATTMODE with the reference prompt
instead of changing the definitions, and Insert > Block gets the Edit
Attribute (Single / Multiple) and attribute display lists.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

locales/ru-RU/opencadstudio.ftl

@@ -4033,6 +4033,15 @@ insert =
     .attdef-define-attributes = Define Attributes
     .attdef-manage-attributes = Manage Attributes
     .attdef-set-base-point = Set Base Point
+    .attdef-attmode-retain = Retain Attribute Display
+    .attdef-attmode-all = Display All Attributes
+    .attdef-attmode-none = Hide All Attributes
+    .attdef-edit-attribute = Edit Attribute
+    .attdef-multiline-editor = Multiline editor
+    .attdef-tag-empty = The tag cannot be empty.
+    .attdef-tag-spaces = The tag may not contain spaces.
+    .attdef-positive = Value must be positive and nonzero.
+    .attdef-angle = Requires valid numeric angle or second point.
 model =
     .create = Создание
     .boolean = Булевы операции