refactor: Simplify and enhance octant portfolio health analysis

- Removed unused headline variables to streamline the code.
- Updated key questions and headlines for clarity and consistency.
- Improved data source references and methodology details for better transparency.
- Enhanced visual elements, including color palette adjustments and layout refinements for better readability.
- Added utility functions for epoch markers and styled stat cards to align with Octant branding.

Author: ccerv1