Upgrade a benefit's eligibility check to a newer published version

[prestoncabe]

Problem

A benefit pins each custom check to one published version (CheckConfig.checkId + checkVersion). When the check's author publishes a newer version, benefits that use the check keep running the old one. That's intended, because published versions are frozen. But nothing in the UI says a newer version exists, and the only way to upgrade is to remove the check from the benefit and add it back, which loses its parameters and alias.

This matters more now that checks can be renamed (#512). A check called "A" at 1.0.0 might be called "B" at 1.1.0, and users would have to recognize it as the same check to upgrade.

Proposal

• In the benefit editor (SelectedEligibilityCheck.tsx), show when a newer published version of a pinned custom check exists, e.g. "A 1.0.0 → B 1.1.0 available".
• Add an upgrade action that repoints the CheckConfig at the newer published version while keeping its parameters and alias.
• Handle changes between versions: parameters that were added (especially required ones), removed, or changed type, and a changed input definition. Ask the user to review the configuration before saving instead of failing silently.
• Leave already-published screeners alone. They should keep running the version they were published with until the screener is republished.

Notes

Published versions of a check are linked by the check's working ID. P-<suffix>-<version> corresponds to W-<suffix>, and EligibilityCheckRepository.getPublishedCheckVersions / getWorkingId already map between them. As of #512, check IDs no longer depend on the check's name, so all published versions of a check can be found by that ID even after a rename.

Open questions:

• Should an upgrade that isn't backward compatible (e.g. a new required parameter) be allowed, or blocked until the user fills in the new parameter?
• Should the same prompt show for library checks, which have their own versioning?