Add domain visualization for HSPG2 and similar genes

[Ahmed-2026]

The current lollipop plot only shows mutation types for genes. We need to add functionality to display and color protein domains for HSPG2 and similar genes. The current implementation uses g3Lollipop to render protein changes, coloring by mutation type. We need to modify this to include domain information and allow coloring by domains in addition to mutation types.

[Ahmed-2026]

For genes with many domains, we may need to implement a filtering mechanism to prevent visual clutter. Next steps:

• Research methods to retrieve domain information for HSPG2 and similar genes.
• Modify the data processing pipeline to include domain information.
• Update the g3Lollipop function call to incorporate domain visualization.
• Test the new functionality with HSPG2 and other genes with known domain structures.