chore: add knip for dead code detection

.github/workflows/knip.yml

@@ -0,0 +1,28 @@
+name: Knip
+
+on:
+  push:
+    branches:
+      - main
+      - master
+  pull_request:
+
+jobs:
+  knip:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: lts/*
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run Knip
+        run: npm run knip

knip.json

@@ -0,0 +1,10 @@
+{
+  "$schema": "https://unpkg.com/knip@6/schema.json",
+  "ignore": ["public/**"],
+  "ignoreDependencies": [
+    "@slidev/cli",
+    "@slidev/theme-default",
+    "lightningcss",
+    "terser"
+  ]
+}