feat(ui): popovers, tooltips, progress; the render3d backend installs itself; duplicate names caught first

- `popover`: a top layer that keeps the pointer and the keyboard, closed by a press outside or Esc.
- `title` tooltips after half a second's rest, styled by .ui-tooltip.
- `<progress>` and `<meter>`.
- Atlases take rows and number cells, and importing ludic.ui/render3d.ludic is enough to draw with
  render3d.
- The compiler reports two declarations of one name before it type-checks, so a package global
  clashing with a program's reads as that, not as 29 type errors.

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

packages/ludic.ui/frame.ludic

@@ -14,7 +14,11 @@ export function ui_show(screen: string, view: UiView, x: float, y: float, w: flo
   sc_update(root)
   fr_pointer(root)
   fc_keys(root)
-  if ui_be != null and ui_be.text != null { fr_draw(root) }
+  if ui_be != null and ui_be.text != null {
+    fr_draw(root)
+    pp_draw_top()
+    tt_draw(root)
+  }
   dv_after(screen, root)
   lc_run(screen)
   nt_fired_run()