hit_ceiling set for downward movement instead of upward

[github-actions]

Issue #734 has been created successfully on GitHub at #734 with:

• Title: [Audit][Medium] hit_ceiling boolean set on downward Y movement when passing through collision
• Label: automated-audit

Summary of the finding: In modules/engine-physics/src/collision.zig:89-93, the hit_ceiling flag is incorrectly set when the player moves downward (move.y < 0). The logic is backwards - hit_ceiling should only fire when moving upward into an overhead block, not when falling and hitting the ground. This is a logic bug where grounded and hit_ceiling can be set incorrectly.

Triggered by scheduled workflow

opencode session  |  github run