Sandbox: "Turn Face Up" only clears the flag, so the real card is never restored (SetFaceState, cf. #3284)

[cuinhellcat]

Summary

The sandbox card menu's Turn Face Up entry clears face_down and nothing else. The permanent's real characteristics stay in back_face, so the card remains a nameless 2/2 with no abilities — visually nothing happens, and no CR 701.27 / CR 708 turn-face-up trigger or replacement fires.

Cause

game/engine_debug.rs, the DebugAction::SetFaceState arm:

if let Some(fd) = face_down {
    validate_object_mut(state, object_id)?.face_down = fd;
}

Two branches below, the transformed arm already carries the fix for exactly this class, with the reason stated:

// CR 701.27a: toggling `transformed` on a DFC must swap
// printed faces, not just flip the flag — a flag-only write
// leaves zone-exit revert applying the wrong characteristics
// (issue #3290 / debug transform tool, issue #3284).

That was #3284, fixed by #3684 by routing through transform::transform_permanent. The face_down branch was never carried over.

Expected

Route a face_down: Some(false) write on a battlefield permanent through morph::turn_face_up, the existing single authority — it restores the stored face, draws the CR 613.7f timestamp, applies the "as ~ is turned face up" replacement, and emits GameEvent::TurnedFaceUp. The flag-only write stays correct only where no stored face exists.

face_down: Some(true) is out of scope here: turning a permanent face down in place has no general engine authority today.

Steps to reproduce

1. Sandbox, click mode on.
2. Put any morph/manifest permanent on the battlefield face down.
3. Card menu → Turn Face Up.
4. The card does not change. Transform on the same card does flip it, because that path goes through the real authority — but it is a transform, not a turn-face-up, so no turn-face-up trigger fires there either.

Not this issue

The separate defect that the engine never offers GameAction::TurnFaceUp in normal play is the still-open half of #6732 / #4381 (see the evidence posted there). This report is only about the sandbox debug action.

[cuinhellcat]

Scope correction while building this: the face-DOWN direction has an authority too — zone_pipeline::apply_face_down_entry_profile, the one the manifest, cloak and face-down-cast paths all run through. Without it a debug turn-face-down leaves the permanent with its name and printed P/T while claiming to be face down, and back_face stays empty, so it can never be turned back up. The fix covers both directions; CR 708.2b (an already-face-down permanent is left alone) falls out of the arm order.

[cuinhellcat]

Correction to my earlier scope note: the face-down direction was taken back out of #7540 (rightly — this issue is the face-up half) and is now tracked on its own as #7541.