C8-02 — HIE pilot: drive the implementation with the harness

Brownfield, Spring Boot + HAPI FHIR. Adopted to L1–L2 and `csda validate` passes. What is missing is driving the implementation with the harness — the part that produces evidence. ### Why it is the sharper of the two pilots It is **brownfield**, and the premise of the earlier assessment was greenfield. A repository that existed before the tool is where the adoption path either holds or does not. ### Read first `mejoras/hie-pilot-runbook.md`. The pack and platform repos live outside this repository, under `~/sandbox/projects/`. --- *Filed while cutting 0.7.0.*