Improve flagship presentation assets

[HarperZ9]

Summary

• replace the README hero with the clearer Project Telos v2 presentation render
• simplify first-screen copy for public readers
• update brand receipt docs with the current renderer and critique gates

Verification

• python tools/render_flagship_heroes.py --check-existing --public-root C:\dev\public --json
• python tools/audit_repo_presentation.py --root C:\dev\public\gather --root C:\dev\public\crucible --root C:\dev\public\index --root C:\dev\public\forum --root C:\dev\public\telos
• git diff --check
• changed-text secret-pattern scan