Add Badge, Chip, and IconButton components with token layers

- Badge: 11 solid-colour variants (navy, info, success, error, warning + light variants, neutral, white) with icon slots
- Chip: bordered interactive element with selected, dismissible, and disabled states
- IconButton: circle/square shapes, 3 variants × 3 intents × 3 sizes, uses lucide-react icons
- Add badge and chip domain token layers to tokens.css
- Configure extendTailwindMerge in cn() to recognise custom font-size utilities (text-small, text-body, etc.)

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

package-lock.json

@@ -37,6 +37,7 @@
         "eslint-plugin-react-refresh": "^0.5.2",
         "eslint-plugin-storybook": "^10.4.0",
         "globals": "^17.6.0",
+        "lucide-react": "^1.16.0",
         "playwright": "^1.60.0",
         "prettier": "^3.8.3",
         "prettier-plugin-tailwindcss": "^0.8.0",
@@ -5167,6 +5168,16 @@
         "yallist": "^3.0.2"
       }
     },
+    "node_modules/lucide-react": {
+      "version": "1.16.0",
+      "resolved": "https://registry.npmjs.org/lucide-react/-/lucide-react-1.16.0.tgz",
+      "integrity": "sha512-dYwyPzb4MEKpGUmNYk3WKWPnMrHs3FKM+q94kAnJrcDIqqn1hq2xY8scaS2ovsOCM5D51ey2gaRG3PBb1vgoYQ==",
+      "dev": true,
+      "license": "ISC",
+      "peerDependencies": {
+        "react": "^16.5.1 || ^17.0.0 || ^18.0.0 || ^19.0.0"
+      }
+    },
     "node_modules/lz-string": {
       "version": "1.5.0",
       "resolved": "https://registry.npmjs.org/lz-string/-/lz-string-1.5.0.tgz",