Expose both shared and static libraries as separate CMake imported targets (ghostty-vt and ghostty-vt-static) rather than toggling between them with BUILD_SHARED_LIBS. The zig build already produces both in a single invocation, so both are always available. The find_package config template is updated to export both targets as ghostty-vt::ghostty-vt and ghostty-vt::ghostty-vt-static. Add a c-vt-cmake-static example that demonstrates linking the static library via FetchContent with -Dsimd=false to avoid C++ runtime dependencies.