feat(registration): add --codex flag and AGENTS.md template
- register_project.sh: parse --additional/--codex as named flags (not
positional), skip MCP check in codex mode, generate AGENTS.md from
agents-codex.template instead of CLAUDE.md + .claude/rules/
- agents-codex.template: new template for Codex repos — HTTP REST session
protocol, inbox/progress curl examples, ADR-001 workplan convention
- Makefile: add register-codex-project target
Driven by onboarding repo-registry (first non-Claude-Code repo, first
repo under the capabilities domain).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
tegwick
1a8afaa371