Fix advocate permission handling and a few command issues

[Y0oshi]

• Characters on an account that was set to Advocate access keep IsAdvocate after the account is demoted, since IsAdvocate isn't ephemeral like the other staff flags and nothing clears it. Command access is checked against IsAdvocate, so the character keeps advocate commands. With OverrideCharacterPermissions enabled (default), it's now cleared on login when the account isn't Advocate and the character doesn't have AdvocateQuest. Bestowed advocates always have AdvocateQuest set, so they're unaffected; an IsAdvocate set manually via /setproperty without AdvocateQuest will be cleared.
• /remove used < while /bestow uses <=, so an advocate could remove another advocate of the same level. The help text says lower level only.
• acehelp <command> and acehelp commands were case-sensitive while running commands isn't.
• When stdin is closed (systemd, docker run without -i, etc.) and ACE_NONINTERACTIVE_CONSOLE isn't set, Console.ReadLine() returns null forever and the command thread spins a core while flooding stdout with the prompt. It now logs and exits. Side effect: sending EOF (Ctrl+D) on an interactive console now closes the prompt until restart.
• Small cleanups in /reportbug (discarded Trim() result, duplicate "item" check) and a leftover Console.WriteLine("OK") in house-select.