feat(graph): node library as a docked panel; shared dock chrome

The node library leaves the overlay and becomes a dock panel (PanelId::
NodeGraph), docked on the right the first time the graph opens and movable
like any other panel; closing it closes the graph. It follows the block
palette's layout: title bar, then a search box with New / Open / Save
beside it, then the categories, of which only Objects starts open. Entries
are clicked (placed at the canvas top-left) or dragged onto the canvas.

The title bar (title, auto-collapse pin, close, drag to re-dock), the
toolbar icon button and the panel frame were copied across Properties,
Block Palette, External References and Browser; they are now
dock::title_bar, dock::tool_button and dock::frame, used by all of them.
Block Palette's two tool buttons gain tooltips, and External References'
Auto / Close tooltips are now translated.

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

src/app/view/mod.rs

@@ -1847,6 +1847,7 @@ bg={bg_ms:.1}ms n={view_count}"
                 crate::ui::dock::PanelId::BlockPalette => self.show_block_palette,
                 crate::ui::dock::PanelId::ExternalReferences => self.show_external_references,
                 crate::ui::dock::PanelId::Browser => self.show_browser,
+                crate::ui::dock::PanelId::NodeGraph => self.show_node_graph,
             }
         };
         let edge_stack = |side: crate::app::config::DockSide| -> Option<Element<'_, Message>> {
@@ -2950,6 +2951,7 @@ impl OpenCADStudio {
                 width,
                 auto_collapse,
             ),
+            crate::ui::dock::PanelId::NodeGraph => tab.graph.panel(width, auto_collapse),
         };
         let divider = dock_divider(id);
         match side {