Checkpoint
One last thing before we move on. Same surface as a write step — but the lesson doesn't complete until this passes.
The capstone's final check: completeness AND wiring. Every subsystem is built; DEPENDS maps each to what it must stand on (the doc depends on everything — it tells the whole story). Verify each built subsystem's dependencies are also built, collecting f"{name} built on unbuilt {dep}" problems. Print f"built: {n}/{total}", the wiring problems (or 'none'), and the verdict: "ship - the system is complete and honestly wired" only when both checks pass. Chapters 35-47, wired end to end — that's the portfolio.