Salvages #27568 by @SerenityTn. Dashboard cron page now lists cron
jobs from all profiles, with profile-aware filter UI and storage
routing. Includes test coverage for cross-profile listing, mutation,
deletion, and validation.
Also fixes orphan conflict markers in config.py left by an earlier
salvage merge (kanban.dispatch_stale_timeout_seconds was double-nested
in HEAD/PR markers from #28452 salvage of #23790).
