Remove dark mode to reduce testing requirements

[bhouston]

Remove dark mode to reduce testing requirements

Problem

The current implementation of dark mode in our documentation adds unnecessary testing requirements and complexity to the project.

Proposed Solution

Remove the dark mode functionality from the Docusaurus configuration to simplify testing and maintenance.

Implementation Details

1. Update docusaurus.config.ts to disable dark mode
2. Remove dark mode related styles from src/css/custom.css
3. Ensure the site maintains a consistent light theme appearance

Benefits

• Reduced testing surface area
• Simplified maintenance
• Consistent user experience across the documentation

Acceptance Criteria

• Dark mode toggle is removed from the UI
• Dark mode styles are removed from the codebase
• Site maintains consistent light theme appearance
• Documentation builds and deploys successfully