This is the Sprint-1 stub for ai.careerplane.engineering.hvac-technician.hvac.refrigeration-cycle.
The fully-generated topic page (sandbox + quiz + AI hints + interactive
tooling) lands in Sprint-2 at
static/content/engineering/HVAC Technician/HVAC/Refrigeration Cycle & Diagnostics — Superheat / Subcooling / Charging/index.html
(per arch/memo.md → D-2026-04-22-13). The
//go:embed all:static directive auto-serves it on the next
container rebuild — no server-code change needed.