diy-materials-estimator@1.0.0

Publisher claims: "Use before any paint, mulch, concrete, drywall, flooring, tile, or fence store run: computes exact material quantities from room/dimensions with real coverage physics (paint spread rate by surface type, mulch depth by purpose, concrete volume + bag yield + mix water), waste factors by pattern, and a consolidated shopping list with buy-unit rounding. Kills the third-trip-to-the-store problem." Observed in sandbox: no network, touches nothing outside the project, writes no memory.