[dajiaohuang]

Summary

GLModel.createMolObj() rebuilds geometry for the selected frame, but previously left an initialized atom's picking-shape arrays intact. The sphere and bond builders append to those arrays, so revisiting a frame retained duplicate picking shapes. Reset sphere, cylinder, line, and triangle lists for clickable/hoverable atoms before rebuilding; non-interactive atoms are unchanged. The opt-in coordinate-replay path does not rebuild and is unaffected.

Related to #860. This change addresses retained picking arrays only; it makes no claim about the separate WebGL geometry-counter or VRAM observations, which were not measured.

Validation

• Offline synthetic check: 200 alternating frame rebuilds kept each interactive frame's shape arrays bounded; also checked the reset runs before the geometry loop.
• node --check on the helper and Jest regression test; git diff --check.
• The committed Jest test and TypeScript/build pipeline were not run because dependencies are absent. The full npm test pipeline generates fixture render tests and runs glcheck; rendering, GPU/context access, and external molecular data are outside this task's limits.

[dkoes]

Thanks!