fix: make readiness probes explicit

[vigneshrajsb]

Summary

• stop inferring readiness probes when readiness is omitted
• remove legacy default readiness probe values from the default service setup path and seed data
• add coverage for services without readiness configuration

Verification

• pnpm run lint
• pnpm test -- --runTestsByPath src/server/services/tests/deployable.test.ts

Notes

• pnpm run ts-check is currently failing on unrelated pre-existing repository issues and was not addressed in this change