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/edit.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"path/filepath"
 
 	"github.com/spf13/cobra"
 )
@@ -31,6 +32,9 @@ func runEdit(cmd *cobra.Command, args []string) error {
 	if editor == "" {
 		return fmt.Errorf("no editor found; set $EDITOR")
 	}
+	if err := os.MkdirAll(filepath.Dir(configPath), 0755); err != nil {
+		return fmt.Errorf("creating config dir: %w", err)
+	}
 	c := exec.Command(editor, configPath)
 	c.Stdin = os.Stdin
 	c.Stdout = os.Stdout