feat(planner): restyle sidebar on tokens (waypoints, notes, days)

Migrate the whole sidebar surface onto the design system:

- SidebarTabs: token tab bar, sage active indicator.
- WaypointSidebar: token surfaces/text; sage number badges; overnight
  marker uses the Badge (stop tone) primitive; route summary + stats
  footer in Geist Mono; destructive delete signalled via bg-nogo.
- NotesPanel + DayBreakdown headers/rows on tokens.
- i18n the previously-hardcoded empty-state string (en + de).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/planner/app/components/NotesPanel.tsx

@@ -94,8 +94,8 @@ export function NotesPanel({ yjs }: NotesPanelProps) {
 
   return (
     <div className="flex h-full flex-col">
-      <div className="border-b border-gray-200 px-4 py-3">
-        <h2 className="text-sm font-medium text-gray-900">
+      <div className="border-b border-border px-4 py-3">
+        <h2 className="text-sm font-medium text-text-hi">
           {t("sidebar.notes")}
         </h2>
       </div>