Refine builder chrome to match dashboard styling

[Copilot]

Builder sidebars/nav were visually off-brand versus the dashboard, command palette, and shortcuts menu; their chrome needed to align with the shared “film” aesthetic without changing behavior.

• Navbar refresh
  • Glassy film-gradient shell, accent glow bar, refined separators
  • Toolbar buttons rebuilt with blurred plates, amber focus rings, richer active/hover states while preserving commands (palette, shortcuts, sidebars, fullscreen, undo/redo, reset, GitHub)
• Sidebar shell overhaul
  • SidebarLayout now uses layered gradients, subtle noise/glow, inset borders, and softened scroll area to match modal/palette styling
  • Layer panel and Inspector headers restyled with amber-lined toggles and elevated pills; logic and tabs unchanged
  • Sidebars adopt transparent chrome (borders handled by inner shells) for cohesive framing with canvas

Example snippet (new sidebar shell):

<SidebarLayout
  header={<div className="rounded-xl p-0.5" style={{ background: 'linear-gradient(120deg, rgba(196,124,46,0.08), rgba(18,16,13,0.9))', border: '1px solid rgba(196,124,46,0.15)' }}>
    {/* tab buttons */}
  </div>}
>
  {/* panel body */}
</SidebarLayout>