HostCacheSourceStamp already edits a module source with a backdated
mtime and expects the PCM cache to be rebuilt. Its own header names the
real danger, a project.so compiled against declarations that no longer
match the process it is loaded into, but it never looked at the
project.so. It now records the file's mtime before the edit and expects
a newer one after it, with project.cpp untouched, so only the stamp can
force the rebuild.
Fails without the previous commit: the stamp was the version string
alone and the project.so was reused.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>