Permissive parser (colon, hyphen, unseparated; case-insensitive; surrounding
whitespace) with canonical lowercase no-separator ToString. Implements
IParsable/ISpanParsable for ASP.NET route binding and ships a System.Text.Json
converter that normalizes on read.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
