## What
Adds `partnerScope` (the partner **Categories** multi-select) to the
output of the two public partner endpoints:
- `list-available-partners` (`/s/partners`)
- `get-partner-by-slug` (`/s/partner-by-slug`)
Additive only — `deploymentExpertise` is kept, so existing consumers
(the current live marketplace) are unaffected.
## Why
Part of the partner marketplace rework. The website marketplace
(companion branch `rk-rework-marketplace-cards`) consumes `partnerScope`
to show/filter partner Categories. The new options + migration live in
the signup app PR #21040.
## Merge order (we'll decide)
Independent diff — can merge in any order. Couplings to keep in mind:
- **Version line:** this branch and #21040 both bump the app
`package.json` version; whoever merges second re-bumps.
- **Deploy (not merge):** the partners app is deployed manually. Deploy
the final combined app (this + #21040) and run `yarn
migrate:partner-scope:prod` **before** the website is deployed.
