fix(knowledge): answer a rejected kb path with 400 KNOWLEDGE_PATH_INVALID instead of 500 - #910

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, astral-sh/setup-uv@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Failed to save: <h2>Our services aren't available right now</h2><p>We're working to restore all services as soon as possible. Please check back soon.</p>0Y93BagAAAADG/upbi3bzRabLaSqrBlwMQ0gxQUEyMDMwODEzMDYyAEVkZ2U=

Failed to restore: Cache service responded with 400