celld already includes sqlite-vec for vector search. Enable it with `"compatibility_flags": ["sqlite_vec"]` in your Wrangler configuration.

See the [vector database example](https://github.com/denoland/celld/tree/main/examples/vectordb), which creates a `vec0` table and runs nearest-neighbor queries. The example uses Durable Object SQL; D1 uses the same underlying SQLite support.