Select Color: Document and Color books tabs

Document tab: every concrete colour the drawing uses (objects, block
definitions and layers), found in one pass when the panel opens, as a
grid of swatches sortable by recently used, most used, colour and colour
number. The recently-used list is now kept per drawing, so the ribbon's
Recent row shows this drawing's colours.

Color books tab: load AutoCAD .acb colour books (remembered in the
settings on desktop), browse them page by page with the page strip,
search by name and see the RGB equivalent. A book colour is applied as
RGB plus its BOOK$NAME identity on objects and layers instead of
dropping the name.

Strings translated into all 22 locales.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013rGmDUNr1hUf4zo1X3dak8

src/app/update/file.rs

@@ -860,6 +860,7 @@ impl OpenCADStudio {
             block_recent: self.block_palette.recent.clone(),
             block_favorites: self.block_palette.favorites.clone(),
             block_libraries: self.block_palette.libraries.clone(),
+            color_books: self.color_book_paths.clone(),
             block_palette_view: self.block_palette.view as u8,
             block_insert: self.block_palette.options.clone(),
             block_mru_list: self.block_mru_list,
@@ -1025,6 +1026,7 @@ impl OpenCADStudio {
         self.block_palette.recent = s.block_recent.clone();
         self.block_palette.favorites = s.block_favorites.clone();
         self.block_palette.libraries = s.block_libraries.clone();
+        self.color_book_paths = s.color_books.clone();
         self.block_palette.view =
             crate::ui::window::block_palette::ViewMode::from_u8(s.block_palette_view);
         self.block_palette.set_options(s.block_insert.clone());