ADR-005: Disable CGO for all build targets (CGO_ENABLED=0)

Status: accepted

Context

Go's CGO facility allows calling C code from Go, but it introduces several complications: cross-compilation from Linux to Windows requires a Windows-capable C cross-compiler (mingw-w64); CGO binaries are dynamically linked against glibc by default, creating runtime dependency on the host's C library version; and the -race detector requires CGO, conflicting with our static-linking posture. The Win32 EventLog API calls use golang.org/x/sys/windows which uses syscall (not CGO) on Windows.

Decision

We will set CGO_ENABLED=0 for all build targets, including both the Linux and Windows binaries. All system calls will use Go's syscall package and golang.org/x/sys, not CGO.

Consequences

All binaries are fully statically linked with no C library dependency. Cross-compilation from Linux to Windows/amd64 works without a Windows C cross-compiler. Binary size is slightly larger than a dynamically-linked build but deployment is simpler (copy binary, run). The trade-off is that CGO-dependent libraries cannot be used; this is acceptable because no CGO dependencies exist in the current codebase. The -race detector cannot be used in test targets (documented in Makefile comment and STATE.md).