test: cover admin pause toggle

[gaoflow]

Summary

• add test coverage for the admin status load and pause/unpause flow
• assert the correct /pause and /unpause endpoints are posted based on loaded state
• cover status reload after successful toggles
• cover initial loading, load errors, and toggle errors without reload

Closes #18

Tests

• npm test -- src/app/admin/page.test.tsx --runInBand
• npm run lint
• npm test -- --runInBand
• npm test -- --coverage --runInBand
• npm run build

Coverage note: app/admin/page.tsx reports 100% statement, branch, function, and line coverage in the coverage run.

[mikewheeleer]

hey @gaoflow, thanks for the effort here 🙏 issue #18 isn't assigned to you though — to keep the campaign fair and avoid duplicate work, please claim/get assigned to it first, then open your PR. closing for now; would love to see it back once it's assigned to you 🙌