Redesign Evidence page with cleaner layout

- Remove redundant Subject Header section
- Make claim the hero with prominent display
- Add trust summary stats (supporting/dissenting/video counts)
- Rename "validations" to "attestations"
- Separate supporting vs dissenting with color-coded borders
- Add video thumbnail with play icon and full player
- Clean up nested boxes for flatter, more readable structure
- Add action buttons: View Graph, View Certificate, Add Attestation
- Move Related Claims to bottom as "More claims about {subject}"
- Add empty state with CTA to be first to attest

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: gvelez17