[UI] FeaturePanel fails to render in Eclipse WindowBuilder Design view

[AmlanDalai]

Problem

Opening FeaturePanel.java in Eclipse WindowBuilder Design view
shows a completely blank canvas with zero components in the
Structure panel. This is a complete parsing failure — WindowBuilder
cannot parse any component in the file.

Evidence

• Structure panel: empty
• Design canvas: completely blank
• Components parsed: 0

Compare this with UIPanel.java which renders all 6 components
correctly in WindowBuilder.

Root Cause

FeaturePanel extends ImageWindow rather than JFrame, and
builds its UI inside showPanel() and multiple helper methods
rather than directly in the constructor. WindowBuilder requires
UI components to be constructed in the constructor to parse them
correctly.

Additionally FeaturePanel uses setLayout(null) with hardcoded
setBounds() coordinates on line 198, making visual editing
impossible even if parsing were fixed.

Proposed Fix

• Investigate feasibility of separating the UI construction from
  ImageWindow dependency
• Refactor UI construction into constructor or initComponents()
  method for WindowBuilder compatibility
• Replace setLayout(null) with GridBagLayout

Related

Directly aligned with the GSoC 2026 goal of streamlining the UI
using WindowBuilder for Eclipse.