chore: add knip

Author: joshunrau

package.json

@@ -21,6 +21,7 @@
     "force-reinstall": "pnpm clean && pnpm install",
     "format": "turbo run format",
     "generate:env": "./scripts/generate-env.sh",
+    "knip": "knip",
     "lint": "turbo run lint",
     "postinstall": "turbo telemetry disable",
     "prepare": "husky",
@@ -62,6 +63,7 @@
     "expect-type": "^0.20.0",
     "husky": "^9.1.7",
     "js-yaml": "^4.1.0",
+    "knip": "^5.46.0",
     "prettier": "^3.4.2",
     "prettier-plugin-astro": "^0.14.1",
     "prettier-plugin-tailwindcss": "^0.6.10",