Successful move-stream responses echoed server position roughly one RTT behind
integrated move_and_slide, so apply_as_snap still fired whenever dh exceeded
the locomotion skip threshold. Treat stream 200 as ack-only: do not emit
authoritative_position_received. Boot GET and click-move verify unchanged.
Update README + GdUnit expectation.
Introduce POST /game/players/{id}/move-stream with ordered targets, full-chain
validation before apply, and PositionStateResponse. Godot client uses camera-
relative WASD, queues samples, and snaps to stream responses; debug builds keep
click-to-move via ground_pick. Update READMEs, E1.M1 snapshot, and tests.