feat: redesign app UI — top nav, clean dashboard, warm branding

- Replace sidebar with top navigation bar (like Airbnb/Nextdoor)
- Redesign dashboard: home cards, coming up tasks, quick action pills
- Remove widget-heavy layout (charts, stats, activity feed)
- Add landing page with hero, features, how-it-works, CTA sections
- Update auth pages with split layout
- Clean white theme with neutral grays, brand orange/teal accents
- Friendly copy across all empty states and page headers
- Add Bricolage Grotesque + Outfit fonts
- Default to light mode

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/ui/card.tsx

@@ -7,7 +7,7 @@ function Card({ className, ...props }: React.ComponentProps<"div">) {
     <div
       data-slot="card"
       className={cn(
-        "flex flex-col gap-6 rounded-xl border bg-card py-6 text-card-foreground shadow-sm",
+        "flex flex-col gap-6 rounded-2xl border bg-card py-6 text-card-foreground shadow-sm transition-shadow",
         className
       )}
       {...props}