feat: order/delay in service files, enable cmd, --all on unit commands

- install/uninstall/start/stop/enable take <name> or --all; *all kept as shortcuts
- add enable (enable at boot + start); startall no longer enables
- order/delay resolved by config.ResolveOrder and written into systemd,
  OpenRC and runit service files (After=/sleep), so they apply at boot
- install --all stops and disables units before removing their files
- update regenerates all installed, enabled units and removes disabled ones
- edit creates the config dir; docs and man page updated
- tests: fake Init for cmd, ResolveOrder, backend ordering output

cmd/update.go

@@ -3,6 +3,8 @@ package cmd
 import (
 	"errors"
 	"fmt"
+	"io"
+	"os"
 
 	"github.com/spf13/cobra"
 	"github.com/warkanum/unitdore/config"
@@ -38,44 +40,73 @@ func runUpdate(cmd *cobra.Command, args []string) error {
 	if err != nil {
 		return err
 	}
-
-	name := args[0]
-	u := cfg.FindUnit(name)
-	if u == nil {
-		return fmt.Errorf("unit %q not found", name)
-	}
-
-	if cmd.Flags().Changed("order") {
-		u.Order = updateOrder
-		fmt.Printf("  order → %d\n", u.Order)
-	}
-	if updateEnable {
-		u.Enabled = true
-		u.DisabledReason = ""
-		fmt.Printf("  enabled\n")
-	}
-	if updateDisable {
-		u.Enabled = false
-		fmt.Printf("  disabled\n")
-	}
-
-	if err := cfg.Save(configPath); err != nil {
-		return err
-	}
-
-	prefix, suffix := cfg.Prefix, cfg.Suffix
 	ini, err := initsys.New(cfg)
 	if err != nil {
 		return err
 	}
 
-	if ini.IsInstalled(*u, prefix, suffix) {
-		if err := ini.Install(*u, prefix, suffix); err != nil {
-			return fmt.Errorf("recreating service file: %w", err)
-		}
-		path, _ := ini.UnitPath(*u, prefix, suffix)
-		fmt.Printf("  ✓ service file recreated: %s\n", path)
+	var order *int
+	if cmd.Flags().Changed("order") {
+		order = &updateOrder
+	}
+	return applyUpdate(cfg, ini, args[0], order, updateEnable, updateDisable, configPath, os.Stdout)
+}
+
+// applyUpdate changes a unit's config, saves it and brings the installed
+// service file in line: re-created if enabled, stopped and removed if disabled.
+func applyUpdate(cfg *config.Config, ini initsys.Init, name string, order *int, enable, disable bool, path string, w io.Writer) error {
+	u := cfg.FindUnit(name)
+	if u == nil {
+		return fmt.Errorf("unit %q not found", name)
 	}
 
+	if order != nil {
+		u.Order = *order
+		fmt.Fprintf(w, "  order → %d\n", u.Order)
+	}
+	if enable {
+		u.Enabled = true
+		u.DisabledReason = ""
+		fmt.Fprintf(w, "  enabled\n")
+	}
+	if disable {
+		u.Enabled = false
+		fmt.Fprintf(w, "  disabled\n")
+	}
+
+	if err := cfg.ResolveOrder(); err != nil {
+		return err
+	}
+	if err := cfg.Save(path); err != nil {
+		return err
+	}
+
+	prefix, suffix := cfg.Prefix, cfg.Suffix
+
+	// The target is stopped and removed if now disabled
+	if ini.IsInstalled(*u, prefix, suffix) && !u.Enabled {
+		svcPath, _ := ini.UnitPath(*u, prefix, suffix)
+		if err := ini.Disable(*u, prefix, suffix); err != nil {
+			return fmt.Errorf("disabling unit: %w", err)
+		}
+		if err := ini.Uninstall(*u, prefix, suffix); err != nil {
+			return fmt.Errorf("removing service file: %w", err)
+		}
+		fmt.Fprintf(w, "  ✓ service stopped and removed: %s\n", svcPath)
+	}
+
+	// Order and enabled state change the After=/delay of other units too, so
+	// every installed, enabled unit is regenerated
+	for i := range cfg.Units {
+		o := cfg.Units[i]
+		if !o.Enabled || !ini.IsInstalled(o, prefix, suffix) {
+			continue
+		}
+		if err := ini.Install(o, prefix, suffix); err != nil {
+			return fmt.Errorf("recreating service file for %s: %w", o.Name, err)
+		}
+		svcPath, _ := ini.UnitPath(o, prefix, suffix)
+		fmt.Fprintf(w, "  ✓ service file recreated: %s\n", svcPath)
+	}
 	return nil
 }