docs(readme): redesign README following Evolith navigation pattern

Apply Evolith's README design language: centered header with badges, hero
infrastructure diagram, compact Quick Navigation Menu (11 rows with icons),
role-based paths (Architect/Backend/Frontend/DevOps/PM/AI), numbered decision
path, deep-dive sections with emoji anchors, UMS vs Evolith comparison table,
contributing section, and branded footer. Preserves the full ADR table with
Evolith relationship column.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: beyondnetPeru