Unify health/version reporting

Parent umbrella issue: #308
Source audit: Weekly tech debt audit: dispatch - 2026-06-03
Source audit date: 2026-06-03

Original recommendation

P2 — Unify health/version reporting: make /api/health use the shared version helper or build-time version and update smoke docs.

Version reporting and docs disagree, which undermines operational smoke checks and support diagnostics.

Evidence:

package.json:3 version is 0.4.4.
src/lib/version.ts resolves the package/build version for UI display.
src/app/api/health/route.ts:5 falls back to 0.1.1.
docs/smoke-checklist.md:30-34 still documents health response version 0.1.13.

\n**Saffron grooming result: promoted to ready**\n\nP2 code fix: unify health/version reporting to shared version helper.