feat(workspace): synchronize folders with server and add folder deletion

internal/storage/sqlite.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"sort"
 	"strings"
 	"sync"
 	"time"
@@ -1435,6 +1436,135 @@ func (s *Store) DeleteDocument(userID, docID string) error {
 	return err
 }
 
+func (s *Store) GetFolders(userID string) ([]string, error) {
+	folderSet := make(map[string]bool)
+
+	// 1. Collect from SQLite documents (owned by user or shared with user)
+	rows, err := s.db.Query(
+		`SELECT DISTINCT folder_path FROM documents 
+		 WHERE (user_id = ? OR id IN (SELECT doc_id FROM doc_shares WHERE user_id = ?)) 
+		   AND is_archived = 0 AND folder_path != ''`,
+		userID, userID,
+	)
+	if err == nil {
+		for rows.Next() {
+			var fp string
+			if err := rows.Scan(&fp); err == nil && fp != "" {
+				clean := filepath.ToSlash(filepath.Clean(fp))
+				parts := strings.Split(clean, "/")
+				var cur string
+				for _, p := range parts {
+					if p != "" && p != "." {
+						if cur == "" {
+							cur = p
+						} else {
+							cur = cur + "/" + p
+						}
+						folderSet[cur] = true
+					}
+				}
+			}
+		}
+		_ = rows.Close()
+	}
+
+	// 2. Scan physical directories on disk in docDir/userID
+	if s.docDir != "" {
+		userDir := filepath.Join(s.docDir, userID)
+		if fi, err := os.Stat(userDir); err == nil && fi.IsDir() {
+			_ = filepath.Walk(userDir, func(path string, info os.FileInfo, err error) error {
+				if err != nil || !info.IsDir() {
+					return nil
+				}
+				if path == userDir {
+					return nil
+				}
+				rel, err := filepath.Rel(userDir, path)
+				if err == nil && rel != "" && rel != "." {
+					clean := filepath.ToSlash(filepath.Clean(rel))
+					parts := strings.Split(clean, "/")
+					var cur string
+					for _, p := range parts {
+						if p != "" && p != "." {
+							if cur == "" {
+								cur = p
+							} else {
+								cur = cur + "/" + p
+							}
+							folderSet[cur] = true
+						}
+					}
+				}
+				return nil
+			})
+		}
+	}
+
+	result := make([]string, 0, len(folderSet))
+	for f := range folderSet {
+		result = append(result, f)
+	}
+	sort.Strings(result)
+	return result, nil
+}
+
+func (s *Store) CreateFolder(userID, folderPath string) (string, error) {
+	clean := filepath.ToSlash(filepath.Clean(strings.TrimSpace(folderPath)))
+	if clean == "" || clean == "." || strings.HasPrefix(clean, "/") || strings.Contains(clean, "..") {
+		return "", fmt.Errorf("ungültiger Ordnerpfad")
+	}
+
+	if s.docDir != "" {
+		targetDir := filepath.Join(s.docDir, userID, clean)
+		if err := os.MkdirAll(targetDir, 0755); err != nil {
+			return "", err
+		}
+	}
+	return clean, nil
+}
+
+func (s *Store) DeleteFolder(userID, folderPath string) ([]string, error) {
+	clean := filepath.ToSlash(filepath.Clean(strings.TrimSpace(folderPath)))
+	if clean == "" || clean == "." || strings.HasPrefix(clean, "/") || strings.Contains(clean, "..") {
+		return nil, fmt.Errorf("ungültiger Ordnerpfad")
+	}
+
+	// Find all documents in this folder and subfolders
+	rows, err := s.db.Query(
+		`SELECT id FROM documents 
+		 WHERE user_id = ? AND (folder_path = ? OR folder_path LIKE ?)`,
+		userID, clean, clean+"/%",
+	)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var deletedDocIDs []string
+	for rows.Next() {
+		var id string
+		if err := rows.Scan(&id); err == nil {
+			deletedDocIDs = append(deletedDocIDs, id)
+		}
+	}
+	_ = rows.Close()
+
+	// Delete from SQLite, pins, shares
+	for _, id := range deletedDocIDs {
+		_, _ = s.db.Exec(`DELETE FROM doc_pins WHERE doc_id = ?`, id)
+		_, _ = s.db.Exec(`DELETE FROM doc_shares WHERE doc_id = ?`, id)
+		_, _ = s.db.Exec(`DELETE FROM documents WHERE id = ? AND user_id = ?`, id, userID)
+	}
+
+	// Remove physical folder and subdirectories from disk
+	if s.docDir != "" {
+		targetDir := filepath.Join(s.docDir, userID, clean)
+		_ = os.RemoveAll(targetDir)
+	}
+
+	return deletedDocIDs, nil
+}
+
 func (s *Store) GetDocShares(docID string) ([]domain.DocShare, error) {
 	rows, err := s.db.Query(
 		`SELECT s.id, s.doc_id, s.user_id, u.email, u.display_name, s.permission, s.created_by, s.created_at