- docs/building.md: explains what each CMake preset (dev, m1-dev, m2-dev,
server-release) is actually for, and how to build voicecat-server + vccli
for manual testing. Linked from CLAUDE.md's doc index.
- core/include/voicecat.h, core/src/voicecat.cpp, core/src/protocol/protocol.h,
server/src/main.cpp: doc-header comments still claimed M0-skeleton/stub
behavior (VC_ERR_NOT_IMPLEMENTED everywhere, "prints what it would do",
protobuf codegen "commented") that M1-M3 made real. Updated to describe
current behavior, with the dev-preset stub fallback noted explicitly where
it still applies.
