feat(pull): add --all support across cloned castles

internal/homesick/core/core.go

@@ -140,6 +140,45 @@ func (a *App) Pull(castle string) error {
 	return runGitWithIO(filepath.Join(a.ReposDir, castle), a.Stdout, a.Stderr, "pull")
 }
 
+func (a *App) PullAll() error {
+	if _, err := os.Stat(a.ReposDir); err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return nil
+		}
+		return err
+	}
+
+	var castles []string
+	err := filepath.WalkDir(a.ReposDir, func(path string, d fs.DirEntry, walkErr error) error {
+		if walkErr != nil {
+			return walkErr
+		}
+		if !d.IsDir() || d.Name() != ".git" {
+			return nil
+		}
+
+		castleRoot := filepath.Dir(path)
+		rel, err := filepath.Rel(a.ReposDir, castleRoot)
+		if err != nil {
+			return err
+		}
+		castles = append(castles, rel)
+		return filepath.SkipDir
+	})
+	if err != nil {
+		return err
+	}
+
+	sort.Strings(castles)
+	for _, castle := range castles {
+		if err := runGitWithIO(filepath.Join(a.ReposDir, castle), a.Stdout, a.Stderr, "pull"); err != nil {
+			return fmt.Errorf("pull --all failed for %q: %w", castle, err)
+		}
+	}
+
+	return nil
+}
+
 func (a *App) Push(castle string) error {
 	if strings.TrimSpace(castle) == "" {
 		castle = "dotfiles"