A depth pass (Depth-Anything / MiDaS-class) runs in the browser at $0 cost to us (§V) and hands the whole system a real spatial map: parallax, depth-of-field, and foreground / mid / background blocking that doubles as a generation control. The point that matters: a measured depth map beats an LLM's idea of one, same honesty line the V/D/C receipts draw, pointed at pixels.