fix(modeling): correct sequence flow layout from corner boundary events

[JhaSourav07]

Describe the Bug Fixed

This PR fixes an issue where sequence flows starting from a corner boundary event and connecting to an element directly on the same axis (e.g., placed completely below or to the side) would generate an awkward, looping layout with an unnecessary extra waypoint.

What changed
Updated getBoundaryEventTargetLayout in BpmnLayouter.js to explicitly check if a target element is strictly on the same vertical or horizontal axis relative to the boundary event. When it is, the layouter now correctly returns 'v' or 'h', allowing the Manhattan layout engine to draw a clean, straight line instead of detouring out to the side.

Steps to verify:

1. Attach a boundary event to the corner of a task.
2. Place another element directly below (or directly to the left/right) of that boundary event.
3. Connect the boundary event to the new element. The sequence flow will now connect in a straight line without additional waypoints.

Fixes #2270

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[Copilot]

Pull request overview

Fixes sequence flow Manhattan layout when connecting from a corner-attached boundary event to a target element that is strictly axis-aligned (directly above/below or left/right), avoiding an unnecessary detour waypoint (issue #2270).

Changes:

• Enhance getBoundaryEventTargetLayout to detect strictly vertical vs strictly horizontal target orientation and return 'v'/'h' accordingly.
• Preserve existing corner-attachment routing logic for diagonal (corner-to-corner/quadrant) target orientations.

Comments suppressed due to low confidence (1)

lib/features/modeling/BpmnLayouter.js:494

• The new verticalTargetOrientation / horizontalTargetOrientation values are computed once, but the later comparisons still call getVerticalOrientation(targetOrientation) / getHorizontalOrientation(targetOrientation) again. Consider reusing the already computed values (and similarly caching the attach orientations) to avoid duplicated parsing and keep the logic easier to follow.

  var verticalTargetOrientation = getVerticalOrientation(targetOrientation),
      horizontalTargetOrientation = getHorizontalOrientation(targetOrientation);

  // If the target is strictly above/below (no horizontal orientation)
  if (verticalTargetOrientation && !horizontalTargetOrientation) {
    return 'v';
  }

  // If the target is strictly left/right (no vertical orientation)
  if (horizontalTargetOrientation && !verticalTargetOrientation) {
    return 'h';
  }

  if (isHorizontal) {
    if (isSame(getVerticalOrientation(attachOrientation), getVerticalOrientation(targetOrientation))) {
      return 'h';
    } else {
      return 'v';
    }
  } else {
    if (isSame(getHorizontalOrientation(attachOrientation), getHorizontalOrientation(targetOrientation))) {
      return 'v';

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Pull request overview

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