feat: redesign UI and UX around design-engineering principles

- Ink-first palette, drop gradients/glow; tabular numbers
- Home: form stays put, results stack below and auto-copy; paste shortens instantly
- Hold-to-delete replaces the delete confirm modal
- Copy buttons morph to a check instead of toasting
- Motion: CSS press feedback, custom ease-out, origin-aware menu, faster exits,
  no animation on frequent/keyboard actions, reduced-motion respected
- Fix: scheme-less URLs ("example.com") were blocked by native validation

Co-Authored-By: Claude Opus 5.5 <[email protected]>

tailwind.config.js

@@ -2,6 +2,8 @@
 export default {
   darkMode: "class",
   content: ["./index.html", "./src/**/*.{ts,tsx}"],
+  // hover: only applies on devices that can actually hover — no sticky taps on phones.
+  future: { hoverOnlyWhenSupported: true },
   theme: {
     extend: {
       fontFamily: {
@@ -12,6 +14,9 @@ export default {
         xl: "0.75rem",
         "2xl": "1rem",
       },
+      transitionTimingFunction: {
+        out: "cubic-bezier(0.23, 1, 0.32, 1)",
+      },
     },
   },
   plugins: [],