docs: finalize ETHOnline submission readiness

[garykocsis]

Summary

• adds the validated 3:55 Standby demo link to the README
• adds AI-assisted development attribution for ChatGPT and Claude Code
• closes project status after completion of implementation, verification, canonical demo, presentation, and ETHOnline submission readiness
• preserves the Session 20 submission-readiness prompt, final status-update prompt, Claude implementation log, and ChatGPT retrospective

Scope

Documentation-only final project closeout.

No Solidity, Foundry tests, frontend, protocol configuration, branding, canonical demo semantics, or verification evidence were changed.

No video binary was added to the repository.

Verification

• git diff --check clean
• README submission-readiness changes independently reviewed: PASS
• final project-status closeout independently reviewed: PASS
• historical project-status content preserved
• official Standby demo: 3:55
• no remaining required implementation or submission-readiness blocker

Result

Standby implementation, verification, canonical demo, presentation, and ETHOnline submission readiness are complete.