Megadev scaling

Decide whether the asset and effect benefit from an ASIC-generated image. The ASIC samples a stamp map into Word RAM; it does not give a VDP sprite a rotation flag, add palette lines or display the result by itself.

• Read ASIC layouts and projection before preparing stamps, trace lines or register values. Read the selected Megadev headers rather than inventing convenience APIs or importing SGDK types.
• Read Ownership and publication for Main/Sub leases, completion, cached snapshots, hidden VRAM uploads and cost accounting. Its performance section explains the measured 5→30 image/s improvements and how to profile copying, HUD work and handoff delays without weakening correctness.
• Read Validation for math, compiled adapters, ares and checks that still need a physical console.

Essential contracts: