docs: retain detailed ProChat closeout evidence

[stevewesthoek]

Summary

• Preserve the exact list of cleaned branches/worktrees and the evidence archive reference.
• Retain the historical browser/LiquidGlass/LCP measurements while clearly distinguishing pre- and post-renderer-correction evidence.
• Keep the closed milestone, deployed runtime, and Mastermind infrastructure handoff consistent.

Validation

• Documentation links are valid.
• ✅ Environment documentation is synchronized.
• Documentation-only; deployment detector must skip production deployment.