feat(editor): zone metadata panel with mapId, displayName, gameplay flags

- Map ID: configurable integer input (0-65535) for private server
  integration. Custom zones default to 9000+ to avoid Blizzard conflicts
- Display Name: editable text field for in-game world map/loading screen
- Description: multi-line text field for zone documentation
- Zone Flags: Allow Flying, PvP Enabled, Indoor, Sanctuary checkboxes
- All fields serialized to zone.json under "flags" key
- Info panel shows quest count alongside objects/NPCs

tools/editor/zone_manifest.cpp

@@ -44,6 +44,14 @@ bool ZoneManifest::save(const std::string& path) const {
     if (hasCreatures) files["creatures"] = "creatures.json";
     j["files"] = files;
 
+    // Zone gameplay flags
+    nlohmann::json flags;
+    flags["allowFlying"] = allowFlying;
+    flags["pvpEnabled"] = pvpEnabled;
+    flags["isIndoor"] = isIndoor;
+    flags["isSanctuary"] = isSanctuary;
+    j["flags"] = flags;
+
     // Audio configuration
     if (!musicTrack.empty() || !ambienceDay.empty()) {
         nlohmann::json audio;
@@ -87,6 +95,15 @@ bool ZoneManifest::load(const std::string& path) {
             }
         }
 
+        // Zone gameplay flags
+        if (j.contains("flags")) {
+            const auto& fl = j["flags"];
+            allowFlying = fl.value("allowFlying", false);
+            pvpEnabled = fl.value("pvpEnabled", false);
+            isIndoor = fl.value("isIndoor", false);
+            isSanctuary = fl.value("isSanctuary", false);
+        }
+
         // Audio configuration
         if (j.contains("audio")) {
             const auto& a = j["audio"];