refactor(editor): extract 8 spawn/snap handlers into cli_spawn_audit.cpp

Moves the NPC spawn / object placer audit + ground-snap
handlers out of main.cpp:
  --snap-zone-to-ground       --snap-project-to-ground
  --audit-zone-spawns         --audit-project-spawns
  --list-zone-spawns          --list-project-spawns
  --diff-zone-spawns          --info-spawn

All operate on creatures.json + objects.json sidecars and
the WHM terrain heightfield via WoweeTerrainLoader.

main.cpp drops 14,628 → 13,887 lines (-741). Behavior verified
by re-running --audit-zone-spawns on a test zone (PASSED with
0 issues, same as before).

tools/editor/cli_spawn_audit.hpp

@@ -0,0 +1,22 @@
+#pragma once
+
+namespace wowee {
+namespace editor {
+namespace cli {
+
+// Dispatch the NPC spawn / object placer audit + ground-snap
+// handlers (8 in this group):
+//   --snap-zone-to-ground       --snap-project-to-ground
+//   --audit-zone-spawns         --audit-project-spawns
+//   --list-zone-spawns          --list-project-spawns
+//   --diff-zone-spawns          --info-spawn
+//
+// All operate on creatures.json + objects.json sidecars and
+// the WHM terrain heightfield via WoweeTerrainLoader.
+//
+// Returns true if matched; outRc holds the exit code.
+bool handleSpawnAudit(int& i, int argc, char** argv, int& outRc);
+
+} // namespace cli
+} // namespace editor
+} // namespace wowee