Rationalize the preset set to match the project's actual state (past M5):
- Rename dev->skeleton (no-deps stub smoke), m1-dev->dev (default dev preset)
- Drop m2-dev (cache-identical to m1-dev)
- Add release preset (optimized + tests on, symbols kept)
- Strip server-release binaries (-s linker flag)
- Add apple-dev/apple-ios/apple-ios-sim scaffolding presets for XCFramework
Add cmake/voicecat-toolchain.cmake wrapper that auto-resolves the vcpkg
triplet from the host platform (x64-mingw-static/x64-linux/arm64-osx) so
the main presets work on Windows/Linux/macOS without per-OS variants.
Update all docs (building.md, CLAUDE.md, README.md, AGENTS.md, deployment.md,
tech-stack.md, client READMEs) and stale preset-name references in code
comments. No C++ behavior changes — the core was already portable.
- 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.
