Closed projection policy for structured bundle-derived diagnostic messages.

Compiler-rendered messages never cross the command boundary. This module admits only exact, bounded detail shapes whose names use the PTC-Lisp symbol grammar, and rebuilds messages from literals after every submitted name is found verbatim in the component source. An unknown-namespace message also requires the compiler's available-namespace list to equal the runtime's canonical public list. It bounds capability names already attested by a frozen bundle before they enter a missing-requirement message. Anything else retains the fixed catalog message.