bd-154: Implement bd daemons stop and restart subcommands

internal/daemon/discovery.go

@@ -212,3 +212,25 @@ func CleanupStaleSockets(daemons []DaemonInfo) (int, error) {
 	}
 	return cleaned, nil
 }
+
+// StopDaemon gracefully stops a daemon by sending shutdown command via RPC
+// Falls back to SIGTERM if RPC fails
+func StopDaemon(daemon DaemonInfo) error {
+	if !daemon.Alive {
+		return fmt.Errorf("daemon is not running")
+	}
+
+	// Try graceful shutdown via RPC first
+	client, err := rpc.TryConnectWithTimeout(daemon.SocketPath, 500*time.Millisecond)
+	if err == nil && client != nil {
+		defer client.Close()
+		if err := client.Shutdown(); err == nil {
+			// Wait a bit for daemon to shut down
+			time.Sleep(200 * time.Millisecond)
+			return nil
+		}
+	}
+
+	// Fallback to SIGTERM if RPC failed
+	return killProcess(daemon.PID)
+}

internal/daemon/kill_unix.go

@@ -0,0 +1,15 @@
+//go:build unix
+
+package daemon
+
+import (
+	"fmt"
+	"syscall"
+)
+
+func killProcess(pid int) error {
+	if err := syscall.Kill(pid, syscall.SIGTERM); err != nil {
+		return fmt.Errorf("failed to send SIGTERM to PID %d: %w", pid, err)
+	}
+	return nil
+}

internal/daemon/kill_windows.go

@@ -0,0 +1,18 @@
+//go:build windows
+
+package daemon
+
+import (
+	"fmt"
+	"os/exec"
+	"strconv"
+)
+
+func killProcess(pid int) error {
+	// Use taskkill on Windows
+	cmd := exec.Command("taskkill", "/PID", strconv.Itoa(pid), "/F")
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("failed to kill PID %d: %w", pid, err)
+	}
+	return nil
+}