fix(fs): differential-test and reclassify basis dirs, delay-updates, fuzzy, dry-run

Each row's exact residual reproduced against rsync 3.4.1:
- basis dirs (--compare/copy/link-dest): FastSync xxHash-verifies a basis hit
  while rsync --size-only installs the wrong same-size basis content.
- --delay-updates: the fixed .fastsync-stage name wipes an unrelated
  destination entry of that name even without --delete; rsync leaves it.
- --fuzzy: deterministic name/size heuristic (10x window), not rsync's matcher.
- --dry-run: would-delete report over-reports the updated file and an
  excluded-but-protected extra, and ordering differs.
Docs: RSYNC_COMPAT tally 109/16/31; HANDOFF item 9. clang-format + cppcheck +
ASan + full suite clean.

src/client/scanner.c

@@ -2264,12 +2264,11 @@ ParallelScanner* parallel_scanner_create_with_options(const char* root_directory
      transfer root itself (it hands the root's immediate subdirectories to
      workers), so capture the root's directory time here. */
   if (options->capture_dir_times &&
-      !scanner_capture_dir_time(options->dir_entries, options->dir_entries_mutex, root_directory,
-                                root_directory, options->relative && options->file_list != NULL,
-                                options->relative_prefix, options->preserve_atimes,
-                                options->preserve_crtimes, options->preserve_xattrs,
-                                options->preserve_acls, options->no_implied_dirs,
-                                options->file_list)) {
+      !scanner_capture_dir_time(
+          options->dir_entries, options->dir_entries_mutex, root_directory, root_directory,
+          options->relative && options->file_list != NULL, options->relative_prefix,
+          options->preserve_atimes, options->preserve_crtimes, options->preserve_xattrs,
+          options->preserve_acls, options->no_implied_dirs, options->file_list)) {
     array_list_delete(root_files);
     array_list_delete(subdirs);
     parallel_scanner_destroy(ps);

src/shared/file.c

@@ -816,8 +816,8 @@ bool file_ensure_directory_secure(const char* path) {
        replacing it is not required for FastSync's transferred directories and
        keeps --keep-dirlinks semantics untouched. */
     struct stat leaf_st;
-    if (fstatat(parent_fd, leaf, &leaf_st, AT_SYMLINK_NOFOLLOW) == 0 &&
-        !S_ISDIR(leaf_st.st_mode) && !S_ISLNK(leaf_st.st_mode)) {
+    if (fstatat(parent_fd, leaf, &leaf_st, AT_SYMLINK_NOFOLLOW) == 0 && !S_ISDIR(leaf_st.st_mode) &&
+        !S_ISLNK(leaf_st.st_mode)) {
       if (unlinkat(parent_fd, leaf, 0) == 0) {
         if (mkdirat(parent_fd, leaf, (mode_t)(0777 & ~(mode_t)file_process_umask())) == 0) {
           created = true;