docs: finalize repository governance evidence

[josiahking]

Summary

Finalizes EvolvePHP 2 Phase 2.7 repository-governance documentation after the verified live GitHub transition.

Changes

• records 2.x as the GitHub default branch
• preserves master as the EvolvePHP 1 legacy line
• documents the active repository rulesets
• documents PR, deletion and force-push protections
• documents the exact required CI checks on 2.x
• records strict/up-to-date required status checks
• updates the normal clone flow for the new default branch
• updates the repository-governance documentation policy test
• records Phase 2.7B in the changelog

Verified Live State

• GitHub default branch: 2.x
• master preserved
• EvolvePHP 1 Legacy Preservation: active
• EvolvePHP 2 Development Branch: active
• no bypass actors
• no branch rename or deletion

Required 2.x checks:

• Policy (PHP 8.4)
• Workspace quality (PHP 8.4)
• Workspace quality (PHP 8.5)

All required checks are bound to GitHub Actions integration ID 15368.

Local Validation

• governance policy: 6 tests, 58 assertions
• README consistency: 13 tests, 130 assertions
• RFC consistency: 11 tests, 126 assertions
• Documentation: 95 tests, 936 assertions
• Architecture: 47 tests, 2,881 assertions
• complete root suite: 142 tests, 3,817 assertions
• PHP 8.4 CI policy: 142 tests, 3,817 assertions
• workspace PHPUnit: 6 tests, 18 assertions
• Deptrac: 0 violations
• PHPStan: no errors
• PHP-CS-Fixer: 0 files fixable
• aggregate workspace quality passed

Scope

Exactly three files:

• README.md
• CHANGELOG.md
• tests/Documentation/EvolvePhp2RepositoryGovernanceTest.php

No workflow, Composer, lockfile, package, RFC, runtime or GitHub-setting changes are included.