Ability to filter business names via ChatSentry or some other auto filter

Filter business names through ChatSentry (or another auto profanity/word filter) so firms can't be named offensively.

Technical notes — Same chokepoint as PAR-53: NameValidator + FirmServiceImpl.createFirm. No profanity/ChatSentry integration exists today; validation is purely the character whitelist, and Hibernia's sanitize does no word filtering. Add a soft-dependency hook in createFirm (and a future renameFirm) that runs the proposed name through ChatSentry/Essentials chat filter if present, else a configurable blocklist in FirmConfiguration — centralized in NameValidator/a new NameFilterService so create + rename share it.