validate_movement now inserts SoundEventEmitter with Footstep events on every successful move. Intensity scales by stance: Sprint 0.8, Walk 0.5, Careful 0.3, Crouch 0.15. Range is Close (3 tiles) for all stances. This completes the sound event pipeline end-to-end: movement produces events → collect_sound_events drains to queue → observer snapshot includes audible events → client bridge receives them. Addresses Tyre critical review item #1 on PR #42. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>