feat(open,generate): implement command parity

internal/homesick/core/core.go

@@ -192,6 +192,68 @@ func (a *App) Destroy(castle string) error {
 	return os.RemoveAll(castleRoot)
 }
 
+func (a *App) Open(castle string) error {
+	if strings.TrimSpace(castle) == "" {
+		castle = "dotfiles"
+	}
+
+	editor := strings.TrimSpace(os.Getenv("EDITOR"))
+	if editor == "" {
+		return errors.New("the $EDITOR environment variable must be set to use this command")
+	}
+
+	castleHome := filepath.Join(a.ReposDir, castle, "home")
+	if info, err := os.Stat(castleHome); err != nil || !info.IsDir() {
+		return fmt.Errorf("could not open %s, expected %s to exist and contain dotfiles", castle, castleHome)
+	}
+
+	castleRoot := filepath.Join(a.ReposDir, castle)
+	cmd := exec.Command("sh", "-c", editor+" .")
+	cmd.Dir = castleRoot
+	cmd.Stdout = a.Stdout
+	cmd.Stderr = a.Stderr
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("open failed: %w", err)
+	}
+
+	return nil
+}
+
+func (a *App) Generate(castlePath string) error {
+	trimmed := strings.TrimSpace(castlePath)
+	if trimmed == "" {
+		return errors.New("generate requires PATH")
+	}
+
+	absCastle, err := filepath.Abs(trimmed)
+	if err != nil {
+		return err
+	}
+
+	if err := os.MkdirAll(absCastle, 0o755); err != nil {
+		return err
+	}
+
+	if err := runGitWithIO(absCastle, a.Stdout, a.Stderr, "init"); err != nil {
+		return err
+	}
+
+	githubUser := ""
+	if out, cfgErr := gitOutput(absCastle, "config", "github.user"); cfgErr == nil {
+		githubUser = strings.TrimSpace(out)
+	}
+
+	if githubUser != "" {
+		repoName := filepath.Base(absCastle)
+		url := fmt.Sprintf("git@github.com:%s/%s.git", githubUser, repoName)
+		if err := runGitWithIO(absCastle, a.Stdout, a.Stderr, "remote", "add", "origin", url); err != nil {
+			return err
+		}
+	}
+
+	return os.MkdirAll(filepath.Join(absCastle, "home"), 0o755)
+}
+
 func (a *App) Link(castle string) error {
 	if strings.TrimSpace(castle) == "" {
 		castle = "dotfiles"