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/link.ludic

@@ -1,6 +1,6 @@
 # link.ludic - each tag in a file that is not an element names a component: the file's own, an
 # unnamed import's exported one, or `as:Name` from the import called `as`
-const LK_OWN: string = " row button input select textarea spacer scroll img hr if else each slot state style component screen import let fragment template provide #text "
+const LK_OWN: string = " row button input select textarea progress meter spacer scroll img hr if else each slot state style component screen import let fragment template provide #text "
 function lib_link(f: UiFile, t: UiTpl) -> void {
   t.sheet = f.sheet
   if not lk_element(t.tag) {