[WIP] Prepare TUI like UI classes and styling

[Copilot]

• Understand issue scope and inspect current UI rendering code paths
• Run baseline tests to verify current repository state
• Introduce small, maintainable TUI-style UI classes/styling primitives
• Wire selected existing UI elements to the new styling primitives with minimal behavior change
• Add focused tests for the new UI styling primitives (if feasible with existing test setup)
• Run targeted tests, then full existing test suite
• Manually verify UI rendering and capture a screenshot of the updated UI
• Run final validation and report completion