Add fountain positional ambient sounds

Implemented fountain sounds as positional audio emitters:

Technical details:
- Added fountainSounds_ library (FountainSmallMediumLoop.wav)
- Fountain type already existed in AmbientType enum but was unused
- 6 second loop interval for fountain sounds
- Volume at 0.8x water volume for gentle bubbling effect
- Max distance: 35 units (same as other water sources)
- Counted in activeWaterCount limit (max 3 water sources at once)
- Spatial 3D audio based on fountain position
- Can be placed via addEmitter(position, AmbientType::FOUNTAIN)

include/audio/ambient_sound_manager.hpp

@@ -106,6 +106,7 @@ private:
     std::vector<AmbientSample> waterSounds_;
     std::vector<AmbientSample> riverSounds_;
     std::vector<AmbientSample> waterfallSounds_;
+    std::vector<AmbientSample> fountainSounds_;
     std::vector<AmbientSample> windSounds_;
     std::vector<AmbientSample> tavernSounds_;
     std::vector<AmbientSample> blacksmithSounds_;

src/audio/ambient_sound_manager.cpp

@@ -66,6 +66,10 @@ bool AmbientSoundManager::initialize(pipeline::AssetManager* assets) {
     waterfallSounds_.resize(1);
     loadSound("Sound\\Doodad\\WaterFallSmall.wav", waterfallSounds_[0], assets);
 
+    // Load fountain sounds
+    fountainSounds_.resize(1);
+    loadSound("Sound\\Doodad\\FountainSmallMediumLoop.wav", fountainSounds_[0], assets);
+
     // Load wind/ambience sounds
     windSounds_.resize(1);
     bool windLoaded = loadSound("Sound\\Ambience\\ZoneAmbience\\ForestNormalDay.wav", windSounds_[0], assets);
@@ -304,7 +308,8 @@ void AmbientSoundManager::updatePositionalEmitters(float deltaTime, const glm::v
             isFire = true;
         } else if (emitter.type == AmbientType::WATER_SURFACE ||
                    emitter.type == AmbientType::RIVER ||
-                   emitter.type == AmbientType::WATERFALL) {
+                   emitter.type == AmbientType::WATERFALL ||
+                   emitter.type == AmbientType::FOUNTAIN) {
             maxDist = MAX_WATER_DISTANCE;
             isWater = true;
         }
@@ -379,6 +384,14 @@ void AmbientSoundManager::updatePositionalEmitters(float deltaTime, const glm::v
                 }
                 break;
 
+            case AmbientType::FOUNTAIN:
+                if (emitter.lastPlayTime >= 6.0f && !fountainSounds_.empty() && fountainSounds_[0].loaded) {
+                    float volume = WATER_VOLUME * 0.8f * volumeScale_ * (1.0f - (distance / maxDist));
+                    AudioEngine::instance().playSound3D(fountainSounds_[0].data, emitter.position, volume);
+                    emitter.lastPlayTime = 0.0f;
+                }
+                break;
+
             default:
                 break;
         }