docs-site: Codex reference gaps — inline-role model and $ca- syntax undocumented (3 gaps)

[SUaDtL]

Branch: feat/pi-support · Tribunal run 2026-07-17-pi-support-branch · Finding: findings/docs-codex/01-03
Reference section never states Codex runs roles inline vs Task-dispatch; command pages show only /ca: syntax; concurrent same-checkout guidance missing.

[SUaDtL]

Verified against PR #313 head 9ed248f4: the Claude Code and Codex reference page now states $ca-<name> as the Codex command form, records that reviewer roles execute inline until agent packaging lands, and gives explicit same-checkout concurrency guidance with the safe append-only and unsafe read-modify-write boundaries. All three documented gaps are implemented on #313, which now carries Closes #332.