Update LSD control plane API auth section to specify X-Tenant-Id

[andrewnguonly]

Overview

Make it super explicit that X-Tenant-Id should be specified in the LSD control plane API request. It's needed for org-scoped API keys and it doesn't hurt to specify it for workspace-scoped API keys.

Be explicit. Reduce user support questions.

Type of change

Type: Update existing documentation

Related issues/PRs

• Slack thread: https://langchain.slack.com/archives/C089RDWTKU4/p1761648613577899

Checklist

• I have read the contributing guidelines
• I have tested my changes locally using docs dev
• All code examples have been tested and work correctly
• I have used root relative paths for internal links
• I have updated navigation in src/docs.json if needed
• I have gotten approval from the relevant reviewers
• (Internal team members only / optional) I have created a preview deployment using the Create Preview Branch workflow

Additional notes

N/A

[github-actions]

Preview ID generated: preview-an28oc-1761674813-75c9ebc

[lnhsingh]

TY!