Make mobile experience feel native

- Disable tap highlight, overscroll bounce, and text-size-adjust
- Add touch-action: manipulation to prevent double-tap zoom
- Font-size 16px on inputs to prevent iOS auto-zoom
- Active press states (scale down) on chips, links, send button
- Remove hover effects on touch devices (mobile only)
- Horizontal scroll suggestion chips with snap (native swipe feel)
- Hide scrollbars on mobile chat area
- Reduce particle count and ambient orb sizes for mobile perf
- Add extra-small screen breakpoint (380px) for iPhone SE/mini
- Safe area insets on left/right edges

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

Author: dachi-dev

src/components/ParticleBackground.jsx

@@ -54,7 +54,10 @@ export default function ParticleBackground() {
       }
     }
 
-    const count = Math.min(80, Math.floor((canvas.width * canvas.height) / 15000));
+    const isMobile = canvas.width < 640;
+    const count = isMobile
+      ? Math.min(30, Math.floor((canvas.width * canvas.height) / 25000))
+      : Math.min(80, Math.floor((canvas.width * canvas.height) / 15000));
     for (let i = 0; i < count; i++) {
       particles.push(new Particle());
     }