In v0.6.0, `celld dev` reads Worker variables only from `.dev.vars` beside the config. It does not read `.env`:

https://github.com/denoland/celld/blob/bad4649d01f0db84cdc9093527e72e64ca7a14bf/crates/celld/dev.rs#L484-L492

`wrangler dev` reads `.dev.vars` first. When there is no `.dev.vars`, it reads `.env` and then `.env.local` from the same directory ([`getVarsForDev`](https://github.com/cloudflare/workers-sdk/blob/1d789fc1ec100eb0308127fd739194bf4a94a3c0/packages/wrangler/src/dev/dev-vars.ts#L78-L102)). The [Cloudflare docs](https://developers.cloudflare.com/workers/configuration/environment-variables/#local-development-with-secrets) give both files for local development:

> Put secrets for use in local development in either a `.dev.vars` file or a `.env` file, in the same directory as the Wrangler configuration file.

`docs/README.md` says that the command reads `.dev.vars` "as `wrangler dev` does", and the help of `celld dev` says the same. But a project that keeps its local variables in `.env` gets none of them under `celld dev`. Each one is `undefined` in the Worker, and celld gives no warning.

## Repro

`wrangler.jsonc`:

```jsonc { "name": "dotenv-repro", "main": "index.js", "compatibility_date": "2026-09-26" } ```

`index.js`:

```js export default { fetch(request, env) { return Response.json({ GREETING: env.GREETING ?? null }); }, }; ```

```sh echo 'GREETING=hello' > .env celld dev curl http://127.0.0.1:9876/ ```

- Expected, as with `wrangler dev`: `{"GREETING":"hello"}` - Actual: `{"GREETING":null}`

With the same line in `.dev.vars` instead, the response is `{"GREETING":"hello"}`.

celld 0.6.0, macOS arm64.