chore(standards): ARFA 1.3 V4.0 standardisation

- composer.json: add extra.arfa.level=1, funding (GitHub sponsors),
  support.docs/security/forum URLs, expand authors with role, keywords
- README.md: premium ARFA 1.3 rewrite — badge header with Psalm L1 badge,
  problem/solution showing legacy duplication anti-pattern, 4 real-world
  use cases (REST API groups, B2B XML, CSV pipeline, query string),
  all 4 encoders reference table, attribute groups example with field
  renaming, CI integration, architecture with ADR decision table,
  project stats, ecosystem table, footer with Packagist badge

Author: walmir-silva