9d74f1a7a3
Add mkdir and mv (rename) FUSE operations to the virtual filesystem: - mkdir: Create directories that persist across remounts via SQLite - mv: Move/rename files and directories with database persistence Changes: - Add directories table to schema for user-created empty dirs - Add tree operations: mkdir, rename_file, rename_directory - Add DB methods for path updates and directory CRUD - Remove MountOption::RO to allow write syscalls - Load stored virtual_path from DB instead of regenerating - Restore user directories on mount from directories table - Upsert files to DB during origin scan POSIX compliant: mv fails with ENOENT if parent doesn't exist (use mkdir first, shell handles -p flag and brace expansion)