fix(sanity-best-practices): use configured dataset in functions example

[codingChewie]

Description

Summary

Updates the Sanity Functions documentation example for "Recursion control with custom HTTP clients" to use the active dataset from context.clientOptions.dataset instead of hardcoding production.

Problem

The current example uses:

/data/mutate/production

That makes the example incorrect for any project using a non-production dataset. If copied as-is, the request can target the wrong dataset or fail unexpectedly.

Fix

Replace the hardcoded dataset with:

/data/mutate/${context.clientOptions.dataset}

This keeps the example aligned with the function runtime context and makes it work across environments.

Testing

Docs-only change.

Verified the example now references the active dataset from function context instead of a hardcoded dataset.

Bug Report

If you find a security vulnerability, do NOT open an issue. Email security@sanity.io instead.

Describe the bug

The Sanity Functions example for "Recursion control with custom HTTP clients" hardcodes the dataset to production in the mutation URL. In non-production datasets, copying this example sends mutations to the wrong dataset.

To Reproduce

Steps to reproduce the behavior:

1. Open the Sanity Functions docs section for "Recursion control with custom HTTP clients".
2. Copy the example using /data/mutate/production.
3. Use it in a function running against a dataset like staging.
4. Trigger the function.
5. Observe that the request targets production instead of the active dataset.

Expected behavior

The example should use context.clientOptions.dataset, for example:

/data/mutate/${context.clientOptions.dataset}

Screenshots

N/A

Which versions of Sanity are you using?

I could not capture a verbatim sanity versions output in this environment because the CLI attempted a network lookup, but the local workspace is using:

• sanity: 5.31.1
• @sanity/functions: 1.4.0
• @sanity/blueprints: 0.15.2
• @sanity/client: 7.24.0
• @sanity/cli: 4.19.0

What operating system are you using?

macOS 26.5.2 (Build 25F84) on Apple Silicon

Which versions of Node.js / npm are you running?

10.9.2

v22.15.0

Additional context

The current example uses:

https://${context.clientOptions.projectId}.api.sanity.io/v2025-05-08/data/mutate/production

It should use the dataset from context.clientOptions.dataset so the example works correctly across environments.

Security issue?

No. This is a documentation/example bug, not a security issue.