refactor(editor): extract format validation into cli_format_validate.cpp

Moves the open-format validation + project-audit handlers out
of main.cpp:

  --validate                    --validate-wom
  --validate-wob                --validate-woc
  --validate-whm                --validate-all
  --validate-project            --validate-project-open-only
  --audit-project               --bench-audit-project
  --bench-validate-project

Also moves the four shared validate*Errors helpers (validateWom/
Wob/Woc/WhmErrors, ~365 lines) into the same module's anonymous
namespace — they were file-scope helpers in main.cpp used only
by these handlers, so co-locating eliminates the cross-TU
coupling.

main.cpp drops 19,446 → 18,396 lines (-1,050). Two build errors
caught during extraction (wrong include path for the WHM loader
header; missing #include for ContentPacker / std::set / std::map);
all fixed before commit.

tools/editor/cli_format_validate.hpp

@@ -0,0 +1,20 @@
+#pragma once
+
+namespace wowee {
+namespace editor {
+namespace cli {
+
+// Dispatch the open-format validation + project audit handlers:
+//   --validate                    --validate-wom
+//   --validate-wob                --validate-woc
+//   --validate-whm                --validate-all
+//   --validate-project            --validate-project-open-only
+//   --audit-project               --bench-audit-project
+//   --bench-validate-project
+//
+// Returns true if matched; outRc holds the exit code.
+bool handleFormatValidate(int& i, int argc, char** argv, int& outRc);
+
+} // namespace cli
+} // namespace editor
+} // namespace wowee