docs: align shared frontend runtime instructions

[Chris0Jeky]

Frontend instructions imported by Claude still described only Codex search tooling, and the documented CI command omitted its working directory. Align the shared instructions with the actual adapter and give the PowerShell command an explicit frontend path that stops on failure.

The root region list and canonical frontend skill now point to frontend/CLAUDE.md and its shared AGENTS import. No runtime, hook, gate, or authority change.

Validation: node scripts/check-doc-links.mjs (663 files, zero broken links), node scripts/check-docs-governance.mjs, node scripts/check-github-ops-governance.mjs, and git diff --check passed. The embedded PowerShell command parses and its frontend package.json target exists. A fresh Claude session and frontend test execution were not needed or claimed for these instruction corrections. OUTSTANDING_TASKS.md remains unchanged.

Closes #2777

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-08T01:14:22.131459Z	b42ce41	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[Chris0Jeky]

Independent Terra review completed against head b42ce41 and base d65bd64. No CRITICAL/HIGH or nonblocking defects.

Verified the actual frontend CLAUDE adapter/import, web region rules, fallback wording against the MCP guide, and explicit PowerShell working directory with immediate failure exit. The canonical Claude skill and Codex adapter intentionally have different orientation content. Source scope is exactly the three declared instruction files.

Root validation: doc links (663 files), docs governance, GitHub operations governance, PowerShell syntax/path proof, and diff checks passed. No fresh runtime session is claimed. Hosted required CI remains the final merge gate.