NEON-29: Deep-descent walk gravity bypass for violet deck vs floor goal

Rays and is_on_floor() can still agree the capsule is supported while the
authoritative click is on the main floor far below (TerracePlatformB lip).

When feet are >0.42 m above the goal surface Y, always add walk gravity and
zero moving floor snap. Shorter drops (e.g. gold step to floor) still use
the probe heuristic only.

client/scripts/player.gd

@@ -80,6 +80,11 @@ const WALK_SUPPORT_PROBE_MIN_UP_DOT: float = 0.42
 ## and reads as “forward support”, so snap + lip [code]is_on_floor()[/code] keep the capsule skating
 ## at deck height until XZ arrival.
 const WALK_CONTINUATION_MAX_BELOW_FEET: float = 0.14
+## If capsule feet are farther above the click’s surface Y than this, always use walk gravity + zero
+## moving snap (rays can still read “support” while [method CharacterBody3D.is_on_floor] hugs a lip).
+## ~0.42 m: **TerracePlatformB** top (~0.6 m) → floor (0) qualifies; **TerraceStepB** (~0.3 m) → floor does
+## not — shallow drops still rely on [method _walk_has_close_floor_probe_below].
+const WALK_DEEP_DESCENT_FEET_ABOVE_GOAL: float = 0.42
 ## CapsuleShape3D in scene: height = 1.0 (cylinder portion), radius = 0.4.
 ## Total half-height from body origin to physical bottom = 0.5 + 0.4 = 0.9
 ## (`CAPSULE_HALF_HEIGHT + PLAYER_CAPSULE_RADIUS`).
@@ -438,8 +443,11 @@ func _walk_has_close_floor_probe_below(move_dir_xz: Vector2) -> bool:
 ## toward a floor click and poisons horizontal motion / slide resolution.
 ## Do apply gravity when [code]is_on_floor()[/code] is still true but there is no walkable surface
 ## within [member WALK_SUPPORT_PROBE_DEPTH] under the foot disk (ledge / void while moving).
+## [param feet_y] is [method capsule_feet_y] for the current body origin (see [member CAPSULE_HALF_HEIGHT]).
 ## [param move_dir_xz] steers multi-sample rays (see [method _walk_probe_xz_offsets]).
-func _apply_walk_air_gravity(delta: float, move_dir_xz: Vector2 = Vector2.ZERO) -> void:
+func _apply_walk_air_gravity(
+	delta: float, feet_y: float, move_dir_xz: Vector2 = Vector2.ZERO
+) -> void:
 	var apply_gravity: bool = not is_on_floor()
 	if (
 		not apply_gravity
@@ -448,6 +456,13 @@ func _apply_walk_air_gravity(delta: float, move_dir_xz: Vector2 = Vector2.ZERO)
 		and not _walk_has_close_floor_probe_below(move_dir_xz)
 	):
 		apply_gravity = true
+	if (
+		not apply_gravity
+		and _has_walk_goal
+		and is_on_floor()
+		and feet_y > _auth_walk_goal.y + WALK_DEEP_DESCENT_FEET_ABOVE_GOAL
+	):
+		apply_gravity = true
 	if apply_gravity:
 		velocity += get_gravity() * delta
 
@@ -459,7 +474,13 @@ func _walk_floor_snap_length(
 		return WALK_STEP_ASSIST_SNAP
 	if _has_walk_goal:
 		# Strong moving snap + lip [code]is_on_floor()[/code] otherwise cancels gravity every tick.
-		if is_on_floor() and not _walk_has_close_floor_probe_below(move_dir_xz):
+		if (
+			is_on_floor()
+			and (
+				not _walk_has_close_floor_probe_below(move_dir_xz)
+				or feet_y > _auth_walk_goal.y + WALK_DEEP_DESCENT_FEET_ABOVE_GOAL
+			)
+		):
 			return 0.0
 		if want_goal_h.length_squared() > 1e-10:
 			var want: Vector3 = want_goal_h.normalized()
@@ -979,7 +1000,7 @@ func _physics_process(delta: float) -> void:
 
 	var walk_move_dir_xz: Vector2 = _resolve_walk_probe_dir_xz(feet_y, want_goal_h)
 
-	_apply_walk_air_gravity(delta, walk_move_dir_xz)
+	_apply_walk_air_gravity(delta, feet_y, walk_move_dir_xz)
 	floor_snap_length = _walk_floor_snap_length(feet_y, want_goal_h, walk_move_dir_xz)
 	move_and_slide()
 	_after_walk_move_and_slide()