The platform collision check in resolve_tilemap_y required vel.y > 0
(strictly falling), so once landing zeroed vel.y the check would fail
next frame. Gravity would add a tiny downward velocity, the platform
would catch it again, and the cycle repeated — causing animation
jitter and repeated landing dust particles.
Change the condition to vel.y >= 0 so platforms resolve when resting.
Extend the ground-stick anti-flicker probe to also detect TILE_PLATFORM
tiles (was TILE_SOLID only), with a proximity guard to preserve
jump-through-from-below behavior.
1961cd353b