Format repository and add APS module specs

[joshuaboys]

Summary

• Format repository markdown, YAML, TOML, and JSON files with oxfmt.
• Add the default .oxfmtrc.json generated by oxfmt --init.
• Add APS module specs for roadmap areas and reconcile this repo's own plan coverage.
• Polish the public repository surface by removing private-origin references, replacing informal dogfooding terminology with plan hygiene language, and normalizing plan ownership to maintainers.

Test Plan

• oxfmt
• ./bin/aps lint plans
• ./bin/aps lint plans/modules
• ./bin/aps lint plans examples test/fixtures/valid
• npx markdownlint-cli "**/*.md"