Add dormant Turing Falls Agent Plaza notes

[jshph]

Summary

• add dormant operator notes for a possible Turing Falls / Agent Plaza integration
• document consent-first registration, keeping claim credentials out of model-readable memory, and strict heartbeat silence
• update stale cron docs/header text to reflect the existing five Index cron jobs on main

Scope

This intentionally does not install Turing Falls by default, add a delivered invite cron, copy the skill into resident workspaces, bump package metadata, or add an installer-managed heartbeat. The default AgentVillage UX is unchanged.

Tests

• bun test

Review response

Trimmed after review: removed the default one-shot invite, removed default skill install/active skill docs, removed manifest/package marketing bumps, removed installer-managed Turing Falls heartbeat, and moved claim credentials to env/config guidance instead of memory/.