feat: multi-modal embeddings + cross-modal retrieval (#117) - #119

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. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

Failed to restore: Failed to GetCacheEntryDownloadURL: Rate limited: Failed request: (429) Too Many Requests: rate limit exceeded