refactor: redesign settings page with sidebar navigation

- Replace single-scroll settings with two-column layout:
  left sidebar nav (Connection, Patterns) + content area
- Consistent back arrow (←) on the left for all navigation levels:
  settings → app, pattern editor → settings list
- Fix CopilotStatusCard path overflow: use break-all for long
  Windows paths, structured detail sections with proper wrapping
- Simplify status card: cleaner status dot indicator, separated
  detail sections with labeled fields and proper text overflow

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/components/PatternEditor.tsx

@@ -224,8 +224,8 @@ export function PatternEditor({
 
   return (
     <div className="flex h-full flex-col">
-      {/* Header — top padding clears the title bar overlay zone */}
-      <div className="flex items-center justify-between border-b border-zinc-800 px-6 pb-3 pt-12">
+      {/* Header — consistent ← navigation */}
+      <div className="flex items-center justify-between border-b border-[var(--color-border)] px-5 pb-3 pt-12">
         <div className="flex items-center gap-3">
           <button
             className="flex size-8 items-center justify-center rounded-lg text-zinc-400 transition hover:bg-zinc-800 hover:text-zinc-200"