feat(editor): add --add-object CLI for headless M2/WMO placement

Mirrors --add-creature for the object placer:

  wowee_editor --add-object <zoneDir> <m2|wmo> <gamePath> <x> <y> <z> [scale]

Lets shell scripts populate objects/buildings without the GUI:

  for tree in 100,200 150,250 200,300; do
    x=${tree%,*}; y=${tree#*,}
    wowee_editor --add-object "$zone" m2 'World/Doodad/Tree.m2' $x $y 0
  done

Loads existing objects.json first then appends, so multiple
invocations build up. Optional scale slot lets the caller set
non-default size (clamped to >0 by the load-time guard).
Verified end-to-end: scaffolded zone → added m2 + wmo → info-objects
reports total=2 with the correct scale range.

tools/editor/main.cpp

@@ -34,6 +34,8 @@ static void printUsage(const char* argv0) {
     std::printf("  --scaffold-zone <name> [tx ty]  Create a blank zone in custom_zones/<name>/ and exit\n");
     std::printf("  --add-creature <zoneDir> <name> <x> <y> <z> [displayId] [level]\n");
     std::printf("                         Append one creature spawn to <zoneDir>/creatures.json and exit\n");
+    std::printf("  --add-object <zoneDir> <m2|wmo> <gamePath> <x> <y> <z> [scale]\n");
+    std::printf("                         Append one object placement to <zoneDir>/objects.json and exit\n");
     std::printf("  --build-woc <wot-base> Generate a WOC collision mesh from WHM/WOT and exit\n");
     std::printf("  --regen-collision <zoneDir>  Rebuild every WOC under a zone dir and exit\n");
     std::printf("  --fix-zone <zoneDir>   Re-parse + re-save zone JSONs to apply latest scrubs/caps and exit\n");
@@ -85,7 +87,7 @@ int main(int argc, char* argv[]) {
         "--info-extract", "--info-zone", "--info-wcp", "--list-wcp",
         "--unpack-wcp", "--pack-wcp",
         "--validate", "--zone-summary",
-        "--scaffold-zone", "--add-creature",
+        "--scaffold-zone", "--add-creature", "--add-object",
         "--build-woc", "--regen-collision", "--fix-zone",
         "--export-png",
         "--convert-m2", "--convert-wmo",
@@ -110,6 +112,11 @@ int main(int argc, char* argv[]) {
                 "--add-creature requires <zoneDir> <name> <x> <y> <z>\n");
             return 1;
         }
+        if (std::strcmp(argv[i], "--add-object") == 0 && i + 6 >= argc) {
+            std::fprintf(stderr,
+                "--add-object requires <zoneDir> <m2|wmo> <gamePath> <x> <y> <z>\n");
+            return 1;
+        }
     }
 
     for (int i = 1; i < argc; i++) {
@@ -1101,6 +1108,57 @@ int main(int argc, char* argv[]) {
                         outPath.c_str(),
                         col.triangles.size(), col.walkableCount(), col.steepCount());
             return 0;
+        } else if (std::strcmp(argv[i], "--add-object") == 0 && i + 5 < argc) {
+            // Append a single object placement to a zone's objects.json.
+            // Args: <zoneDir> <m2|wmo> <gamePath> <x> <y> <z> [scale]
+            std::string zoneDir = argv[++i];
+            std::string typeStr = argv[++i];
+            std::string gamePath = argv[++i];
+            namespace fs = std::filesystem;
+            if (!fs::exists(zoneDir)) {
+                std::fprintf(stderr, "add-object: zone '%s' does not exist\n",
+                             zoneDir.c_str());
+                return 1;
+            }
+            wowee::editor::PlaceableType ptype;
+            if (typeStr == "m2") ptype = wowee::editor::PlaceableType::M2;
+            else if (typeStr == "wmo") ptype = wowee::editor::PlaceableType::WMO;
+            else {
+                std::fprintf(stderr, "add-object: type must be 'm2' or 'wmo'\n");
+                return 1;
+            }
+            glm::vec3 pos;
+            try {
+                pos.x = std::stof(argv[++i]);
+                pos.y = std::stof(argv[++i]);
+                pos.z = std::stof(argv[++i]);
+            } catch (const std::exception& e) {
+                std::fprintf(stderr, "add-object: bad coordinate (%s)\n", e.what());
+                return 1;
+            }
+            wowee::editor::ObjectPlacer placer;
+            std::string path = zoneDir + "/objects.json";
+            if (fs::exists(path)) placer.loadFromFile(path);
+            placer.setActivePath(gamePath, ptype);
+            placer.placeObject(pos);
+            // Optional scale after coordinates.
+            if (i + 1 < argc && argv[i + 1][0] != '-') {
+                try {
+                    float scale = std::stof(argv[++i]);
+                    if (std::isfinite(scale) && scale > 0.0f) {
+                        // Set scale on the just-placed object (last in list).
+                        placer.getObjects().back().scale = scale;
+                    }
+                } catch (...) {}
+            }
+            if (!placer.saveToFile(path)) {
+                std::fprintf(stderr, "add-object: failed to write %s\n", path.c_str());
+                return 1;
+            }
+            std::printf("Added %s '%s' to %s (now %zu total)\n",
+                        typeStr.c_str(), gamePath.c_str(), path.c_str(),
+                        placer.getObjects().size());
+            return 0;
         } else if (std::strcmp(argv[i], "--add-creature") == 0 && i + 4 < argc) {
             // Append a single creature spawn to a zone's creatures.json.
             // Args: <zoneDir> <name> <x> <y> <z> [displayId] [level]