Redesign Select Color panel: index and true color tabs

Replace the old index page and the iced_aw ColorPicker popup with one
Select Color panel:

- Index Color tab: standard colors, ACI 10-249 grid, grays; arrow keys
  move through the palette.
- True Color tab: HSB, RGB and gradient-field modes built on two new
  widgets (GradientSlider, ColorArea) and iced_aw NumberInput boxes,
  an editable hex field and a nearest/exact index color button.
- Current/New swatch: clicking Current reverts. A mixed selection opens
  on the color of the most recently drawn object with *VARIES* on top.
- Color field accepts an index, a color name, r,g,b or hex.
- Enter confirms, Esc cancels, other keys stay in the panel.
- New labels translated in all 22 locales.

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

src/app/view/mod.rs

@@ -2474,42 +2474,15 @@ bg={bg_ms:.1}ms n={view_count}"
             }
         }
 
-        if let Some((_, current)) = self.color_pick_target.as_ref() {
-            match self.color_picker_tab {
-                super::ColorPickerTab::Index => {
-                    let content =
-                        crate::ui::color_select::index_color_page(*current, &self.recent_colors);
-
-                    crate::ui::modal::modal(
-                        base,
-                        t!("Select Color"),
-                        content,
-                        Message::CloseColorPicker,
-                        self.modal_offset,
-                        crate::ui::modal::ModalOptions::NOTICE,
-                    )
-                }
-
-                super::ColorPickerTab::TrueColor => {
-                    let initial = crate::ui::properties::acad_color_display(*current).0;
-                    let modal_base = crate::ui::modal::backdrop(base, Message::CloseColorPicker);
-
-                    iced_aw::ColorPicker::new(
-                        true,
-                        initial,
-                        modal_base,
-                        // Cancel inside True Color returns to the indexed page instead
-                        // of closing the whole CAD colour picker.
-                        Message::ColorPickerTabChanged(super::ColorPickerTab::Index),
-                        |color| {
-                            Message::ColorWindowPick(crate::ui::color_select::iced_to_acad_color(
-                                color,
-                            ))
-                        },
-                    )
-                    .into()
-                }
-            }
+        if let Some(picker) = self.color_picker.as_ref() {
+            crate::ui::modal::modal(
+                base,
+                t!("Select Color"),
+                picker.view(),
+                Message::CloseColorPicker,
+                self.modal_offset,
+                crate::ui::modal::ModalOptions::NOTICE,
+            )
         } else {
             base
         }