Original vikon_core sync_root_dir.php only downloads files that are
missing locally or have size 0. Added local file size check before
downloading to avoid re-fetching 14GB+ of existing files.
Original vikon_core Path::getFsPathByModule() returns moduleRoot/files/,
not moduleRoot. Root FM files, 3-letter subdirs, and new files all go
under files/ directory. index.html etc come from core ZIP, not FM sync.
- UpdateCoreAction: split syncDirFiles into syncRootDir (→module root)
and syncSubDir (→files/{dirId})
- SyncFilesAction: same split, matching original PHP vikon_core behavior
- index.html, file_stubs/ etc go to module root
- 3-letter FM codes (eib, eid, rir) go inside files/
Root files (index.html, file_stubs/) and non-3-letter directories now go
to module root where VIKON expects them, not into files/ subdirectory.
dir_name from FM API is relative to module root.
F4ilji