NEON-29: Ledge peel via move_and_collide + fallback gravity

Direct global_position.y edits may not stick vs Jolt after move_and_slide.
Use move_and_collide for the peel step so motion goes through physics.

If get_gravity() is near zero, use -9.81 for peel, walk air, and idle air.

client/scripts/player.gd

@@ -85,6 +85,8 @@ const WALK_CONTINUATION_MAX_BELOW_FEET: float = 0.14
 ## ~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
+## [method get_gravity] can be ~0 with missing/odd project defaults; ledge peel + airborne walk still need a pull.
+const WALK_FALLBACK_GRAVITY_Y: float = -9.81
 ## 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`).
@@ -454,7 +456,7 @@ func _walk_has_close_floor_probe_below(move_dir_xz: Vector2) -> bool:
 ## velocity does **not** move the body off a terrace lip; use [method _apply_walk_post_slide_ledge_peel].
 func _apply_walk_air_gravity(delta: float, _feet_y: float, _move_dir_xz: Vector2 = Vector2.ZERO) -> void:
 	if not is_on_floor():
-		velocity += get_gravity() * delta
+		velocity += _effective_gravity(delta) * delta
 
 
 ## After [method move_and_slide], peel the capsule down when the authoritative goal is below the feet
@@ -479,8 +481,11 @@ func _apply_walk_post_slide_ledge_peel(
 	if not peel:
 		_walk_ledge_peel_vy = 0.0
 		return
-	_walk_ledge_peel_vy += get_gravity().y * delta
-	global_position.y += _walk_ledge_peel_vy * delta
+	_walk_ledge_peel_vy += _effective_gravity(delta).y * delta
+	var dy: float = _walk_ledge_peel_vy * delta
+	if absf(dy) > 1e-9:
+		# Raw [code]global_position[/code] edits can be ignored/overwritten vs Jolt sync after [method move_and_slide].
+		move_and_collide(Vector3(0.0, dy, 0.0), false, safe_margin, false)
 
 
 func _walk_floor_snap_length(
@@ -576,6 +581,13 @@ func _set_horizontal_velocity_from_nav_path_or_goal(fallback_goal_xz: Vector3) -
 	velocity.y = 0.0
 
 
+func _effective_gravity(_delta: float) -> Vector3:
+	var g: Vector3 = get_gravity()
+	if g.length_squared() < 0.25:
+		return Vector3(0.0, WALK_FALLBACK_GRAVITY_Y, 0.0)
+	return g
+
+
 static func capsule_feet_y(body_origin_y: float, capsule_half_height: float) -> float:
 	return body_origin_y - capsule_half_height
 
@@ -595,7 +607,7 @@ func _physics_idle_tick(delta: float) -> void:
 		# cannot reach the lower floor — the capsule idles in mid-air until a new walk goal runs.
 		velocity.x = 0.0
 		velocity.z = 0.0
-		velocity += get_gravity() * delta
+		velocity += _effective_gravity(delta) * delta
 		floor_snap_length = FLOOR_SNAP_MOVING
 	move_and_slide()