ResultHolderStatus.javaFour-level result status for ResultHolder. Values: OK (success), WARNING (success with issues — operation completed but something is noteworthy), ERROR (failure — operation could not complete), FAILED (fatal failure — critical error, likely a bug or system issue). I18n keys: common.resultholder.ok, etc. Has isIn(ResultHolderStatus...) varargs helper for multi-value checks.
The distinction between ERROR and FAILED is subtle: ERROR means "the user's request couldn't be fulfilled" (validation failure, permission denied), while FAILED means "something went wrong that shouldn't have" (NullPointerException, database connection failure). In the UI, ERROR messages are shown as red error banners; FAILED may show a generic "internal error" page.