Add reasoningDefault support under agents.defaults and preserve the existing per-agent/session/inline override order.
Includes authorization gating for configured reasoning state, /status coverage, config schema/docs baseline updates, and regression tests for the reply and status paths. Also carries the related cron startup-run preservation fix and CI test stabilization needed for this PR branch.
Validated locally with pnpm check:changed, the focused Vitest bundle for touched gateway/cron/auto-reply/plugin-sdk/tooling tests, pnpm config:docs:check, and git diff --check. GitHub checks are green on the merged head; Greptile latest visible review is 4/5 with no P0/P1 findings.
