feat(frontend): mobile bottom nav, chatbot overhaul, responsive polish

- MobileNav: safe-area-aware bottom tab bar (< md), mirrors desktop nav
- Chatbot: timestamps, per-message copy, retry-on-fail, auto-grow composer,
  MarkdownLite (XSS-safe React nodes, no dangerouslySetInnerHTML)
- AppFrame: NavRail (md+) + MobileNav (< md) + bottom content padding
- Design system: SignalTone ambient (signal/amber/vermilion) driving WebGL
  haze + topbar status pill; SectionHeader/MetricTile; globals.css tokens
- Views: dashboard hero + AmbientField, analysis/media responsive grids

services/frontend/src/components/shell/topbar.tsx

@@ -35,7 +35,9 @@ export function TopBar() {
     <header className="sticky top-0 z-40 flex items-center gap-3 px-4 py-3 pt-[calc(0.75rem+env(safe-area-inset-top))] sm:gap-4 sm:px-5 sm:py-3.5">
       <div className="flex min-w-0 items-baseline gap-2 sm:gap-3">
         <span className="eyebrow hidden sm:inline">GMW</span>
-        <h1 className="display truncate text-[1.25rem] text-ink sm:text-[1.5rem]">{label}</h1>
+        <h1 className="display truncate text-[1.25rem] text-ink sm:text-[1.5rem]">
+          {label}
+        </h1>
       </div>
 
       <div className="ml-auto flex items-center gap-2 sm:gap-3">