[Work Packet]: Verify health checks validate schema presence

[juscghwe]

Goal

Confirm that the backend health checks validate the correct database/table availability semantics instead of accidentally checking table contents.

The checks should prove that required tables/schema are reachable and usable without depending on rows being present.

Suggested branch name

backend/verify-health-schema-checks

Expected task size

Small: one focused session

Scope

• Review existing backend health check queries.
• Confirm they check table/schema availability, not row contents.
• Replace any content-dependent checks such as broad SELECT * FROM ... probes with minimal schema/table checks where appropriate.
• Document the intended health-check semantics in nearby code or module docs if needed.

Explicit non-goals / boundaries

• Do not redesign the full health model.
• Do not add frontend health UI work here.
• Do not change medication-domain schema decisions.
• Do not require seeded table contents for a healthy state.

Files / areas likely affected

• backend health modules
• SQLite/persistence health helpers
• dev-notes health checks
• backend tests or smoke checks
• docs near health/persistence modules

Definition of done

• Health checks do not depend on table rows existing.
• Required tables/schema are still validated meaningfully.
• Any previous SELECT * FROM ...-style content probe is either removed or justified.
• Tests or local validation cover an empty-table healthy state.
• Any follow-up health behavior questions are captured separately.

Validation

• Run the backend health checks against an empty but migrated database.
• Run existing backend smoke/integration checks.
• Confirm health output stays healthy when required tables exist but contain zero rows.

Follow-up ideas

• Add dedicated schema migration validation later.
• Add deeper readiness diagnostics after the M1 foundation is stable.