Tine Array Geometry

The layout of a plucked-tine board as pure maths: the kalimba's centre-out fan and the music box comb's monotonic run, tine lengths from the clamped-free bar's square-root law, and one slot table driving the SVG paths, the hit test and the tip-to-bridge strike reading. No React, no DOM — so the ink and the touch targets cannot drift apart, and the whole thing is testable in Node.