chore(deps): upgrade Jest past 26 to drop deprecated request/jsdom stack

[jimmyandrade]

Summary

Jest 26.6.3 pulls jest-environment-jsdom@26 → jsdom@16 → deprecated:

• request@2.88.2
• request-promise-native@1.0.9
• har-validator@5.1.3

(We already have a narrow overrides.request.qs pin for security; that does not clear the deprecation warnings.)

Parent inventory: #445 (Cluster C).

Scope

• Upgrade jest, babel-jest, and related test tooling to a line that no longer depends on the deprecated request stack (Jest 28+ with modern jsdom, or at least a jsdom that dropped request).
• Update Jest config / snapshots if required by the major bump.
• Keep Node 18 CI (npm ci --legacy-peer-deps) green.

Acceptance criteria

• No request / request-promise-native / har-validator deprecation warnings on install from the Jest tree
• Full Jest suite passes
• Remove obsolete overrides.request only if nothing else still needs it

Related

• chore(deps): clear npm install deprecation warnings #445 Inventory of npm deprecation warnings