feat(editor): zone audio configuration panel

- Zone manifest gains audio fields: musicTrack, ambienceDay,
  ambienceNight, musicVolume, ambienceVolume
- Serialized to/from zone.json under "audio" key
- Info panel: collapsable "Zone Audio" section with text inputs for
  music/ambience paths and volume sliders
- Preset selector: Elwynn Forest, Durotar, Darkshore, Dungeon, None
- ZoneManifest stored persistently on EditorApp so audio settings
  survive between exports (was recreated each save)
- Custom zones can now specify their own background music and ambient
  soundscapes via zone.json

tools/editor/editor_app.cpp

@@ -997,7 +997,7 @@ void EditorApp::exportZone(const std::string& outputDir) {
 
     // Write zone manifest (for client loading)
     // Scan output directory for all exported tiles (includes adjacent tiles)
-    ZoneManifest manifest;
+    ZoneManifest& manifest = zoneManifest_;
     manifest.mapName = loadedMap_;
     manifest.displayName = loadedMap_;
     manifest.tiles.push_back({loadedTileX_, loadedTileY_});

tools/editor/editor_app.hpp

@@ -150,6 +150,7 @@ private:
     float autoSaveInterval_ = 300.0f;
     bool autoSaveEnabled_ = true;
     bool showQuitConfirm_ = false;
+    ZoneManifest zoneManifest_;
 
     // Recent zones
     struct RecentZone { std::string mapName; int tileX; int tileY; };
@@ -162,6 +163,7 @@ public:
     void showToast(const std::string& msg, float duration = 3.0f);
     const std::vector<Toast>& getToasts() const { return toasts_; }
     const std::vector<RecentZone>& getRecentZones() const { return recentZones_; }
+    ZoneManifest& getZoneManifest() { return zoneManifest_; }
     bool isAutoSaveEnabled() const { return autoSaveEnabled_; }
     void setAutoSaveEnabled(bool v) { autoSaveEnabled_ = v; }
     float getAutoSaveInterval() const { return autoSaveInterval_; }

tools/editor/editor_ui.cpp

@@ -2473,6 +2473,51 @@ void EditorUI::renderPropertiesPanel(EditorApp& app) {
                 ImGui::Text("Height: %.0f-%.0f (avg %.0f)", minH, maxH, sumH / count);
         }
 
+        // Zone audio configuration
+        if (app.hasTerrainLoaded() && ImGui::CollapsingHeader("Zone Audio")) {
+            auto& manifest = app.getZoneManifest();
+            static char musicBuf[256] = {};
+            static char ambDayBuf[256] = {};
+            static char ambNightBuf[256] = {};
+            std::strncpy(musicBuf, manifest.musicTrack.c_str(), sizeof(musicBuf) - 1);
+            std::strncpy(ambDayBuf, manifest.ambienceDay.c_str(), sizeof(ambDayBuf) - 1);
+            std::strncpy(ambNightBuf, manifest.ambienceNight.c_str(), sizeof(ambNightBuf) - 1);
+
+            if (ImGui::InputText("Music##audio", musicBuf, sizeof(musicBuf)))
+                manifest.musicTrack = musicBuf;
+            if (ImGui::InputText("Ambience (Day)##audio", ambDayBuf, sizeof(ambDayBuf)))
+                manifest.ambienceDay = ambDayBuf;
+            if (ImGui::InputText("Ambience (Night)##audio", ambNightBuf, sizeof(ambNightBuf)))
+                manifest.ambienceNight = ambNightBuf;
+            ImGui::SliderFloat("Music Vol", &manifest.musicVolume, 0.0f, 1.0f, "%.2f");
+            ImGui::SliderFloat("Ambience Vol", &manifest.ambienceVolume, 0.0f, 1.0f, "%.2f");
+
+            if (ImGui::BeginCombo("Presets##audioPreset", "Select...")) {
+                if (ImGui::Selectable("Elwynn Forest")) {
+                    manifest.musicTrack = "Sound\\Music\\ZoneMusic\\Forest\\ForestDay.mp3";
+                    manifest.ambienceDay = "Sound\\Ambience\\GlueScreenAmbience.wav";
+                }
+                if (ImGui::Selectable("Durotar")) {
+                    manifest.musicTrack = "Sound\\Music\\ZoneMusic\\Barrens\\BarrensDay.mp3";
+                    manifest.ambienceDay = "Sound\\Ambience\\GlueScreenAmbience.wav";
+                }
+                if (ImGui::Selectable("Darkshore")) {
+                    manifest.musicTrack = "Sound\\Music\\ZoneMusic\\Darkshore\\DarkshoreDay.mp3";
+                    manifest.ambienceDay = "Sound\\Ambience\\GlueScreenAmbience.wav";
+                }
+                if (ImGui::Selectable("Dungeon")) {
+                    manifest.musicTrack = "Sound\\Music\\ZoneMusic\\Dungeon\\DungeonAmbience.mp3";
+                    manifest.ambienceDay = "";
+                }
+                if (ImGui::Selectable("None (silent)")) {
+                    manifest.musicTrack = "";
+                    manifest.ambienceDay = "";
+                    manifest.ambienceNight = "";
+                }
+                ImGui::EndCombo();
+            }
+        }
+
         if (app.getTerrainEditor().hasUnsavedChanges())
             ImGui::TextColored(ImVec4(1, 0.8f, 0.3f, 1), "* Unsaved (Ctrl+S to save)");
         else

tools/editor/zone_manifest.cpp

@@ -44,6 +44,17 @@ bool ZoneManifest::save(const std::string& path) const {
     if (hasCreatures) files["creatures"] = "creatures.json";
     j["files"] = files;
 
+    // Audio configuration
+    if (!musicTrack.empty() || !ambienceDay.empty()) {
+        nlohmann::json audio;
+        if (!musicTrack.empty()) audio["music"] = musicTrack;
+        if (!ambienceDay.empty()) audio["ambienceDay"] = ambienceDay;
+        if (!ambienceNight.empty()) audio["ambienceNight"] = ambienceNight;
+        audio["musicVolume"] = musicVolume;
+        audio["ambienceVolume"] = ambienceVolume;
+        j["audio"] = audio;
+    }
+
     std::ofstream f(path);
     if (!f) { LOG_ERROR("Failed to write zone manifest: ", path); return false; }
     f << j.dump(2) << "\n";
@@ -76,6 +87,16 @@ bool ZoneManifest::load(const std::string& path) {
             }
         }
 
+        // Audio configuration
+        if (j.contains("audio")) {
+            const auto& a = j["audio"];
+            musicTrack = a.value("music", "");
+            ambienceDay = a.value("ambienceDay", "");
+            ambienceNight = a.value("ambienceNight", "");
+            musicVolume = a.value("musicVolume", 0.7f);
+            ambienceVolume = a.value("ambienceVolume", 0.5f);
+        }
+
         return !mapName.empty();
     } catch (const std::exception& e) {
         LOG_ERROR("Failed to parse zone manifest: ", e.what());

tools/editor/zone_manifest.hpp

@@ -17,6 +17,13 @@ struct ZoneManifest {
     bool hasCreatures = false;
     std::string description;
 
+    // Audio configuration
+    std::string musicTrack;         // Background music file path
+    std::string ambienceDay;        // Daytime ambient sound
+    std::string ambienceNight;      // Nighttime ambient sound
+    float musicVolume = 0.7f;
+    float ambienceVolume = 0.5f;
+
     bool save(const std::string& path) const;
     bool load(const std::string& path);
 };