Mockup F — Cost-meter detail flyover (hover state)

What this surfaces

• Flyover renders on hover over the 🎨 Skins chip in the budget bar. Same interaction pattern as native tooltips, but with embedded structure and an action button.
• Breakdown by cost source — base / normal-map / emissive / alpha-blend, matching the §2.8.1 cost-formula coefficients. Lets the builder understand why the cost is what it is.
• Selected-face vs visible-scene split — helps the builder distinguish their contribution from the rest of the scene.
• Adjust-quality button opens Mockup E. Closes the loop: cost is high → understand why → adjust threshold OR adjust content.

ADR-117 cross-coupling

• This footer reflects the proposed ADR-117 user-facing labels — Build / Movers / Skins instead of the current LI / Dyn / Obj.
• The 🎨 Skins chip folds the ADR-126 PBR cost into ADR-117's texture-memory dimension rather than getting its own footer chip — same conceptual category ("how rich are surface materials"), one chip to look at, breakdown available on demand.
• Texture memory (24 MB / 80 MB) and PBR cost (12 / 5000 units) coexist in this flyover because they're both contributors to perceived "skin richness."

Pending tech-track answers

• Q3 — cost-meter placement (UX recommends footer-of-BuildPanel persistent across all 5 tabs since cost is prim-scoped, not tab-scoped).
• Q6 — fold PBR into Skins vs separate chip. UX recommends fold.
• Q9 — ADR-117 ownership.