feat: add participants.tsv preview table, AI summary tooltip, and navigation refactor

[elainefan331]

This PR includes three main updates enhancing usability, clarity, and navigation in the dataset detail and metadata panels.

1. Participants Table Preview

   • Displays participants.tsv content in a modal table for quick participant-level reference.

2. AI Summary Tooltip

   • Added an info icon with a tooltip explaining the meaning of the AI Summary section.

3. Navigation Refactor

   • Replaced the back button with a Home icon and database path.
   • Provides a cleaner and more intuitive navigation experience.