diff --git a/.claude/.gitignore b/.claude/.gitignore
new file mode 100644
index 0000000..f9cb41a
--- /dev/null
+++ b/.claude/.gitignore
@@ -0,0 +1,3 @@
+worktrees/
+*.local.*
+
diff --git a/package.json b/package.json
index 8b75b85..8c6ea32 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
   "scripts": {
     "dev": "vite",
     "build": "vite build",
+    "preinstall": "npx only-allow pnpm",
     "preview": "vite preview",
     "check": "svelte-check --tsconfig ./tsconfig.json",
     "prepare": "husky"