feat(cli): add apply subcommand

internal/cli/profile.go

@@ -0,0 +1,83 @@
+package cli
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// NewProfile returns the `profile` subcommand with `list` and `use`.
+func NewProfile() *cobra.Command {
+	var root string
+	rootFlag := func(c *cobra.Command) {
+		c.Flags().StringVar(&root, "root", "", "canonical root (default ~/.config/harness-sync)")
+	}
+
+	list := &cobra.Command{
+		Use:   "list",
+		Short: "List available profiles",
+		RunE: func(cmd *cobra.Command, _ []string) error {
+			r, err := resolveRoot(root)
+			if err != nil {
+				return err
+			}
+			entries, err := os.ReadDir(filepath.Join(r, "profiles"))
+			if err != nil {
+				return err
+			}
+			names := make([]string, 0, len(entries))
+			for _, e := range entries {
+				if strings.HasSuffix(e.Name(), ".yaml") {
+					names = append(names, strings.TrimSuffix(e.Name(), ".yaml"))
+				}
+			}
+			sort.Strings(names)
+			for _, n := range names {
+				_, _ = fmt.Fprintln(cmd.OutOrStdout(), n)
+			}
+			return nil
+		},
+	}
+	rootFlag(list)
+
+	use := &cobra.Command{
+		Use:   "use <name>",
+		Short: "Set active profile (rewrites config.yaml)",
+		Args:  cobra.ExactArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			r, err := resolveRoot(root)
+			if err != nil {
+				return err
+			}
+			target := args[0]
+			profPath := filepath.Join(r, "profiles", target+".yaml")
+			if _, err := os.Stat(profPath); err != nil {
+				return fmt.Errorf("profile %q not found at %s", target, profPath)
+			}
+			configPath := filepath.Join(r, "config.yaml")
+			existing, _ := os.ReadFile(configPath)
+			updated := setActiveProfile(string(existing), target)
+			return os.WriteFile(configPath, []byte(updated), 0o600)
+		},
+	}
+	rootFlag(use)
+
+	cmd := &cobra.Command{Use: "profile", Short: "Manage profiles"}
+	cmd.AddCommand(list, use)
+	return cmd
+}
+
+func setActiveProfile(existing, name string) string {
+	lines := strings.Split(existing, "\n")
+	for i, l := range lines {
+		if strings.HasPrefix(l, "active_profile:") {
+			lines[i] = "active_profile: " + name
+			return strings.Join(lines, "\n")
+		}
+	}
+	return strings.TrimRight(existing, "\n") + "\nactive_profile: " + name + "\n"
+}