Handbook: Design system updates are up to Mike T (#44868)

- @noahtalerman: Context: We introduced this new [multi-select/filter UI
component](https://www.figma.com/design/mCPegRjoFdpMem1PLMF1BF/-41519----44591---43769-Dashboard-widgets?node-id=5537-18651&t=jBcSqVENnj8ZRna5-1)
w/ the new dashboard widgets and @melpike discovered this on her own.
This new notification process would have sped up that discovery.

<img width="534" height="393" alt="Screenshot 2026-05-07 at 9 16 56 AM"
src="https://github.com/user-attachments/assets/eaa67612-2bb0-49d2-96c4-94aba4aa2ee5"
/>

---------

Co-authored-by: kiloconnect[bot] <240665456+kiloconnect[bot]@users.noreply.github.com>
Co-authored-by: melpike <79950145+melpike@users.noreply.github.com>
Co-authored-by: Noah Talerman <47070608+noahtalerman@users.noreply.github.com>

handbook/product-design/README.md

@@ -78,7 +78,7 @@ At Fleet, like [GitLab](https://about.gitlab.com/handbook/product-development-fl
 
 Additionally:
 
-- To make changes to the design system or a component (e.g. button border-radius or modal width), [make a new request](https://fleetdm.com/handbook/company/product-groups#making-a-request).
+- To make changes to [Fleet's design system](https://fleetdm.com/handbook/company/product-groups#design-system) (e.g. button border-radius, modal width, or a new UI component), [make a new request](https://fleetdm.com/handbook/company/product-groups#making-a-request). Changes to the design system are up to the [Head of Design](#team). Once approved, it's up to the Head of Design to post in [#help-design](https://fleetdm.slack.com/archives/C02A8BRABB5) and @ mention all [Product Designers](#team) so they're aware.
 
 - If the story has a requester and the title and/or description change during drafting (scope change), notify the requester. The customer DRI should confirm that the updated scope still meets the requester's needs.