feat(cmd): add startall and stopall commands for unit management

* Implement startall to enable and start all installed units
* Implement stopall to stop and disable all running units

cmd/stopall.go

@@ -0,0 +1,60 @@
+package cmd
+
+import (
+	"fmt"
+	"sort"
+
+	"github.com/spf13/cobra"
+	"github.com/warkanum/unitdore/config"
+	"github.com/warkanum/unitdore/systemd"
+)
+
+var stopallCmd = &cobra.Command{
+	Use:   "stopall",
+	Short: "Stop and disable all running managed units",
+	Long:  `Stopall runs 'systemctl disable --now' for all enabled, installed units.`,
+	RunE:  runStopall,
+}
+
+func init() {
+	rootCmd.AddCommand(stopallCmd)
+}
+
+func runStopall(cmd *cobra.Command, args []string) error {
+	cfg, err := config.Load(configPath)
+	if err != nil {
+		return err
+	}
+
+	prefix, suffix := cfg.Prefix, cfg.Suffix
+
+	// Reverse order for shutdown
+	units := make([]config.Unit, len(cfg.Units))
+	copy(units, cfg.Units)
+	sort.Slice(units, func(i, j int) bool {
+		if units[i].Order != units[j].Order {
+			return units[i].Order > units[j].Order
+		}
+		return units[i].Name > units[j].Name
+	})
+
+	stopped := 0
+	failed := 0
+
+	for _, u := range units {
+		if !systemd.IsInstalled(u, prefix, suffix) {
+			continue
+		}
+		fmt.Printf("  ■ stopping: %s...\n", systemd.ServiceName(u, prefix, suffix))
+		if err := systemd.Disable(u, prefix, suffix); err != nil {
+			fmt.Printf("  ✗ failed: %s: %v\n", u.Name, err)
+			failed++
+		} else {
+			fmt.Printf("  ✓ stopped: %s\n", u.Name)
+			stopped++
+		}
+	}
+
+	fmt.Printf("\nDone. Stopped: %d  Failed: %d\n", stopped, failed)
+	return nil
+}