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_test.go

@@ -0,0 +1,48 @@
+//go:build !windows
+
+package deploy
+
+import (
+	"os/exec"
+	"testing"
+)
+
+// TestWorkerProcessRunningNotFound checks the negative path (process absent).
+// On any CI/local box the test binary name is extremely unlikely to exist as a
+// running process by that exact name, so pgrep should return non-zero.
+func TestWorkerProcessRunningNotFound(t *testing.T) {
+	// Use a name that will never be a running process.
+	if workerProcessRunning("__aetherforge_nonexistent_9z__") {
+		t.Error("should return false for a process that does not exist")
+	}
+}
+
+// TestWorkerProcessRunningCurrent verifies detection works when a process IS
+// running. We use "go" (the go toolchain itself) since it's always present
+// during a test run inside go test.
+func TestWorkerProcessRunningCurrent(t *testing.T) {
+	// pgrep -x matches exact process names; "go" may or may not match
+	// depending on how go test spawns subprocesses. Use the test binary itself.
+	name := "go"
+	out, err := exec.Command("pgrep", "-x", name).Output()
+	if err != nil || len(out) == 0 {
+		t.Skipf("pgrep -x go found nothing; skip live-process check (pgrep not in PATH?)")
+	}
+	// If pgrep found it, our function must also find it.
+	if !workerProcessRunning(name) {
+		t.Errorf("workerProcessRunning(%q) should be true when pgrep finds it", name)
+	}
+}
+
+// TestWorkerProcessRunningStripsExeSuffix ensures that Windows-style ".exe"
+// suffixes in process names are stripped before the pgrep call so the same
+// config name can be used on both platforms.
+func TestWorkerProcessRunningStripsExeSuffix(t *testing.T) {
+	// Process "crypto-miner-agent.exe" → pgrep -x "crypto-miner-agent"
+	// We can't guarantee it's running, but we can confirm it doesn't panic
+	// and returns a bool.
+	result := workerProcessRunning("__nonexistent__.exe")
+	if result {
+		t.Error("should not find __nonexistent__.exe as a running process")
+	}
+}