docs: refresh public GitHub identity

[Alex0158]

What changed

• add a concise root README for the public GitHub landing page
• document the root README as a navigation-only exception to the Markdown placement policy
• allow that exact root README in the docs structure guard
• reopen the existing Production custom-domain governance task with 2026-08-06 live evidence and explicit repair gates

GitHub repository presentation was also corrected directly through the GitHub API:

• description: Emorapy — guided reflection and repair after relationship conflict.
• website: https://emorapy.co.uk
• topics: current product and stack terms only
• empty Wiki and Projects surfaces: disabled
• v1.3.3 release note: legacy CJ reference explicitly marked as historical context

Why

The repository rename had completed, but the public About text and website still presented the legacy product identity. The repository also had no root README, while current Production custom-domain claims no longer matched live HTTPS, routing, and version evidence.

Impact and boundaries

This PR changes documentation and the documentation placement guard only. It does not change runtime code, DNS, Railway, Vercel, CORS, EAS, or release configuration. Legacy hostnames remain available for compatibility and rollback. Canonical-domain remediation stays fail-closed behind the recorded decision and release gates.

Validation

• git diff --cached --check
• Node.js 24.18.0: npm run docs:check
  • naming governance passed
  • docs structure passed
  • docs truth/ledger/metadata checks passed

npm ci reported the repository's existing dependency audit state of 12 vulnerabilities (2 low, 8 high, 2 critical). No dependency changes or automated audit fixes are included in this scoped PR.