[FEAT] Animation : expose unity_animation_set_object_reference_curve for 2D sprite-frame animation (issue #30 by VM233). Keyframes take an assetPath plus an optional sub-asset name to select one sprite from a sliced sheet; the plugin fails closed on any unresolvable keyframe. Companion plugin route animation/set-object-reference-curve

[CLEAN] Counts : advanced tier 268 -> 269 in the pinned tier test and in manifest.json's description/long_description/tool blurb, which state the total in four places