cao-contributing

Contribute changes to the CAO (CLI Agent Orchestrator) codebase — the local dev loop, the CI gate map, and the pre-PR checklist. Use when the user says "open a PR", "why did CI fail", "run the checks before I push", "the mypy/Code Quality job is red", "add a test and verify coverage", "bump a dependency", "the uv.lock diff is noisy", "a CVE blocks the dependency gate", or when making any code change intended to land on a branch/PR. Covers uv-based build/test/lint, lockfile and CVE-floor rules, the ci.yml jobs and their pass/fail semantics, and the golden rules that stop a green-locally / red-in-CI surprise. Not for authoring agent skills, building providers/plugins/MCP-apps, or operating running sessions.