UTF-8000: Unlimited UTF-8

UTF-8000 extends UTF-8 to arbitrarily long code units while preserving all existing properties and special cases. It introduces no new special cases beyond ASCII and 2-byte UTF-8, maintaining the same content-bit patterns and overlong-encoding checks. The specification clarifies how to split the highest bits of the first byte into self-synchronization and start bits, then stripe start bits across continuation bytes to support larger code units.