Read Illustrator EPS and .ai layers from their editing data

An Illustrator EPS is a flattened page plus, after %%EOF, an editing copy of
the document; a PDF-compatible .ai carries the same in its private data.
Importing only the page lost layer names, order, visibility, hidden layers
and hidden objects and hidden text.

- eps: read the editing copy (Zstandard %AI24_DataStream, older zlib
  %AI9_DataStream) into layers, sublayers, groups, compound paths, clip
  groups and hidden objects, run by the existing PostScript interpreter.
  Falls back to the page, with a warning, when a shown layer uses an
  operator that isn't read or the art differs from the page by over 5%.
- eps: read the text document (ate.rs) to place type on hidden layers and
  objects; the page's type is matched to the file's text objects by
  position (pieces of a line included) and kept with the nearest one when
  none claims it. Area type and type on a path are left out with a note.
- pdf/engine: .ai files go through the same reader.
- engine/cli: a file whose import left things out isn't overwritten unless
  asked (acknowledgeLoss, --replace-lossy).
- eps: font names re-encoded with a *<n> suffix resolve to their family.
- i18n: es/it/ru for the new import messages; ROADMAP updated.

Container and text-document formats were inferred from user-owned files; the
Adobe file format specification was not read.

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

crates/doc/src/clipnest.rs

@@ -21,6 +21,8 @@ pub struct Clip {
     pub id: u32,
     /// The region and its rule; `None` for a plain group.
     pub region: Option<(BezPath, FillRule)>,
+    /// The group is hidden (its art is in it, not shown).
+    pub hidden: bool,
 }
 
 /// Deepest nesting of clips, and of groups, an importer records ([`nest`] goes one level deeper
@@ -78,5 +80,7 @@ fn clip_group(doc: &mut Document, c: &Clip, items: Drawn, depth: usize) -> Arc<N
         children.push(Arc::new(path));
     }
     children.extend(nest_at(doc, items, depth + 1));
-    Arc::new(Node::new(doc.alloc_id(), NodeKind::Group { children, clip: c.region.is_some() }))
+    let mut group = Node::new(doc.alloc_id(), NodeKind::Group { children, clip: c.region.is_some() });
+    group.visible = !c.hidden;
+    Arc::new(group)
 }