fix(annotative): make scale-manager rename and edits actually persist

Double-click rename did nothing and ratio edits were lost when switching
scales — and on drawings saved by other programs nothing could be edited
at all.

- Fallback scales were virtual (no Scale objects), so edit/rename no-oped;
  materialize the standard set into real staged objects when the manager
  opens, reverted on close unless applied.
- On third-party DWGs the mutators walked the root named-objects dict ->
  ACAD_SCALELIST, which can be unreachable, and matched dictionary keys
  that are internal ids (*A1, A0) rather than scale names. Locate the
  scale-list dict robustly and match scales by object name + handle.
- Rename rows inline via double-click; repair a dangling current-scale
  header pointer on staged rollback.
- Stage text/mleader style-manager edits on switch so they persist like
  the scale manager.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ui/popup/scale_popup.rs

@@ -91,7 +91,7 @@ fn scale_row(label: String, active: bool, msg: Message) -> Element<'static, Mess
 }
 
 fn manage_row() -> Element<'static, Message> {
-    button(text("Manage scales...").size(11).color(CHECK_COLOR))
+    button(text("Manage...").size(11).color(CHECK_COLOR))
         .on_press(Message::ScaleManagerOpen)
         .style(|_: &Theme, status| button::Style {
             background: Some(Background::Color(match status {