feat(editor): add --bulk-rename-by-magic recursive recovery flag

Walks a directory tree, identifies every file by 4-byte magic,
and renames each one to use the correct .w* extension.
Counterpart to single-file --rename-by-magic for the case
where a whole asset bundle came in with mangled extensions
(extracted from a tarball that lost suffixes, downloaded with
CDN-rewritten names, dumped from a database BLOB column).

Same safety semantics as the single-file flag: conflicts are
skipped without --force, --dry-run prints the planned moves
without touching the filesystem. Reports per-file PASS/FAIL/
CONFLICT and a final summary (renamed / skipped-conflict /
already-correct / unrecognized counts). Exits 1 if any
rename failed (e.g. permission errors) so it can be wired
into CI as a gate.

tools/editor/cli_arg_required.cpp

@@ -135,6 +135,7 @@ const char* const kArgRequired[] = {
     "--info-wliq", "--validate-wliq",
     "--export-wliq-json", "--import-wliq-json",
     "--info-magic", "--summary-dir", "--rename-by-magic",
+    "--bulk-rename-by-magic",
     "--gen-animations", "--gen-animations-combat", "--gen-animations-movement",
     "--info-wani", "--validate-wani",
     "--export-wani-json", "--import-wani-json",