Context

Slack thread: https://slack.com/archives/C04S2HVU99V/p1770692743021709

Problem

The dashboard generation guide does not clarify that risingwave_dashboard is obsolete and that risingwave_dev_dashboard is the recommended, better-organized, and more comprehensive option. This can lead users to build or maintain the deprecated dashboard.

Suggested Fix

• Update the dashboard generation guide to explicitly state that risingwave_dashboard is obsolete.
• Add a clear recommendation to use risingwave_dev_dashboard instead.
• If applicable, include a short rationale (better organized and comprehensive) and a brief migration note or pointer to where the dev dashboard is generated.