Several fixes and enhancements

- Add task property corruption test helpers - Extract queue orphan pruning - Move CLI handlers into commands module - Add object exists helper - Add task update-and-reindex helper - Print values in prop list - Scope prop keys to a task - Add namespace property key listing - Revert "List properties in active namespace" - Limit reopen picker to closed tasks - Add interactive reopen search - Add properties page to web UI - List properties in active namespace - Add property get command - Update tsk skill drop workflow - Rename closed-on drop flag - Extract task reference helpers - Repair calculated properties in clean - Add calculated task reference properties