refactor: migrate remaining components to Design System v4

111 files across 14 directories: common, tree-editor, kb-accelerator,
copilot, assistant, analytics, library, procedural, procedural-editor,
public, script-editor, ui, admin, step-library.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/common/ContextMenu.tsx

@@ -71,12 +71,12 @@ export function ContextMenu({ position, items, onClose }: ContextMenuProps) {
         left: position.x,
         top: position.y,
       }}
-      className="min-w-[200px] rounded-xl border border-border bg-card p-1 shadow-lg backdrop-blur-md"
+      className="min-w-[200px] rounded-xl border border-[#1e2130] bg-[#14161d] p-1 shadow-lg"
     >
       {items.map((item) => (
         <div key={item.id}>
           {item.separator && (
-            <div className="my-1 border-t border-border" />
+            <div className="my-1 border-t border-[#1e2130]" />
           )}
           <button
             onClick={() => {
@@ -87,11 +87,11 @@ export function ContextMenu({ position, items, onClose }: ContextMenuProps) {
               'flex w-full items-center gap-2 rounded-lg px-3 py-2 text-sm transition-colors',
               item.variant === 'danger'
                 ? 'text-rose-400 hover:bg-rose-500/10'
-                : 'text-foreground hover:bg-brand-border'
+                : 'text-[#e2e5eb] hover:bg-brand-border'
             )}
           >
             {item.icon && (
-              <span className="flex h-4 w-4 items-center justify-center text-muted-foreground">
+              <span className="flex h-4 w-4 items-center justify-center text-[#848b9b]">
                 {item.icon}
               </span>
             )}