Own generic WordPress agent guidance and runtime permissions

[chubes4]

Summary

• move concise WordPress Source and Abilities guidance into wp-coding-agents
• preserve the existing read-only-reference wording near the top of composed AGENTS.md
• add native mutation protections for OpenCode, Claude Code, and Codex without adding a custom OS sandbox
• preserve existing runtime configuration and decline conflicting Codex sandbox profiles

Runtime policy

• OpenCode: permission.edit denies for installed plugins, themes, and wp-includes
• Claude Code: project-anchored Edit deny rules for the same paths
• Codex 0.138+: :workspace-derived permission profile with read-only path carve-outs

These are defense-in-depth controls. OpenCode and Claude Code arbitrary subprocesses remain outside their file-tool permission guarantees.

Verification

• ./tests/agents-md-guidance.sh
• ./tests/opencode-local-plugin-path.sh
• ./tests/repair-opencode-json.sh
• ./tests/claude-code-permissions.sh
• ./tests/claude-code-hook-scope.sh
• ./tests/codex-permissions.sh
• ./tests/codex-runtime.sh
• ./tests/bridge-render.sh
• ./tests/homeboy-agents-md.sh

Follow-ups

Merge this PR before the corresponding Data Machine and Data Machine Code ownership cleanup PRs.

AI assistance

OpenAI gpt-5.6-sol via OpenCode drafted the implementation, tests, and PR description. Chris Huber reviewed the architecture and remains responsible for the changes.