feat: git-installable (prepare build), ship design docs in package, add ADOPT.md for Claude Code

package.json

@@ -8,7 +8,15 @@
   "repository": { "type": "git", "url": "https://git.alwisp.com/jason/ui-kit.git" },
   "publishConfig": { "registry": "https://git.alwisp.com/api/packages/jason/npm/" },
   "sideEffects": ["**/*.css"],
-  "files": ["dist", "tailwind-preset.cjs", "src/styles/globals.css"],
+  "files": [
+    "dist",
+    "tailwind-preset.cjs",
+    "src/styles/globals.css",
+    "DESIGN.md",
+    "PRODUCT.md",
+    "MIGRATION.md",
+    "README.md"
+  ],
   "exports": {
     ".": { "types": "./dist/index.d.ts", "import": "./dist/index.js" },
     "./preset": "./tailwind-preset.cjs",
@@ -22,7 +30,7 @@
     "dev": "tsup --watch",
     "typecheck": "tsc --noEmit",
     "design:detect": "impeccable detect src/",
-    "prepublishOnly": "npm run build"
+    "prepare": "npm run build"
   },
   "dependencies": {
     "@radix-ui/react-dialog": "^1.1.4",