Add Codex CLI as a second MCP registration target

[jserv]

deploy.sh detects claude and codex independently and now degrades gracefully when only one (or neither) is installed. Per-client registration failures no longer abort the install or strand the uninstall before rm: failures are counted and surfaced in the final banner.

src/mcp/setup.rs grows a Host::Codex variant with matching aliases ("codex", "codex-cli"), ALL_HOSTS entry, generate_for_host arm, and round-trip tests. cargo test 1375 passed; clippy clean; shellcheck -x clean except a pre-existing SC2005 in get_script_dir.

---

Summary by cubic

Adds Codex CLI as a second MCP registration target and updates install/uninstall/status to detect and register with whichever clients are available. Improves reliability with safer process handling and per-client errors that don’t abort the flow.

• New Features

  • scripts/deploy.sh now detects claude and codex independently and registers with those found.
  • Codex support with CODEX_MCP_NAME (default zhtw) and codex mcp add zhtw -- /path/to/zhtw-mcp, with validation via codex mcp get --json.
  • zhtw-mcp setup codex via new Host::Codex (aliases: codex, codex-cli) in src/mcp/setup.rs.
  • README/docs updated with Codex commands and examples.

• Bug Fixes

  • Install/uninstall no longer abort on per-client registration errors; failures are counted and shown at the end. Uninstall leaves Codex registrations that point elsewhere.
  • Safer process stop: anchored, escaped path patterns prevent killing unrelated processes.
  • Status now reports binary freshness, checks Codex registration (and mismatches), and uses the same safe process matching.

^{Written for commit e3def40. Summary will update on new commits.}