Wire SMSG_PLAY_MUSIC to MusicManager via SoundEntries.dbc lookup

Add PlayMusicCallback to GameHandler so SMSG_PLAY_MUSIC (and the
vanilla 0x0103 alias) dispatch a soundId to the registered handler
instead of being silently consumed. Application.cpp registers the
callback, loads SoundEntries.dbc, resolves the first non-empty
Name+DirectoryBase into an MPQ path, and passes it to MusicManager
for non-looping playback. Resolves the TODO in the SMSG_PLAY_MUSIC
handler.

include/game/game_handler.hpp

@@ -937,6 +937,12 @@ public:
     using AchievementEarnedCallback = std::function<void(uint32_t achievementId)>;
     void setAchievementEarnedCallback(AchievementEarnedCallback cb) { achievementEarnedCallback_ = std::move(cb); }
 
+    // Server-triggered music callback — fires when SMSG_PLAY_MUSIC is received.
+    // The soundId corresponds to a SoundEntries.dbc record. The receiver is
+    // responsible for looking up the file path and forwarding to MusicManager.
+    using PlayMusicCallback = std::function<void(uint32_t soundId)>;
+    void setPlayMusicCallback(PlayMusicCallback cb) { playMusicCallback_ = std::move(cb); }
+
     // Mount state
     using MountCallback = std::function<void(uint32_t mountDisplayId)>;  // 0 = dismount
     void setMountCallback(MountCallback cb) { mountCallback_ = std::move(cb); }
@@ -2088,6 +2094,9 @@ private:
 
     // ---- Forced faction reactions (SMSG_SET_FORCED_REACTIONS) ----
     std::unordered_map<uint32_t, uint8_t> forcedReactions_;  // factionId -> reaction tier
+
+    // ---- Server-triggered music ----
+    PlayMusicCallback playMusicCallback_;
 };
 
 } // namespace game

src/core/application.cpp

@@ -2096,6 +2096,31 @@ void Application::setupUICallbacks() {
         }
     });
 
+    // Server-triggered music callback (SMSG_PLAY_MUSIC)
+    // Resolves soundId → SoundEntries.dbc → MPQ path → MusicManager.
+    gameHandler->setPlayMusicCallback([this](uint32_t soundId) {
+        if (!assetManager || !renderer) return;
+        auto* music = renderer->getMusicManager();
+        if (!music) return;
+
+        auto dbc = assetManager->loadDBC("SoundEntries.dbc");
+        if (!dbc || !dbc->isLoaded()) return;
+
+        int32_t idx = dbc->findRecordById(soundId);
+        if (idx < 0) return;
+
+        // SoundEntries.dbc (WotLK): fields 2-11 = Name[0..9], field 22 = DirectoryBase
+        const uint32_t row = static_cast<uint32_t>(idx);
+        std::string dir = dbc->getString(row, 22);
+        for (uint32_t f = 2; f <= 11; ++f) {
+            std::string name = dbc->getString(row, f);
+            if (name.empty()) continue;
+            std::string path = dir.empty() ? name : dir + "\\" + name;
+            music->playMusic(path, /*loop=*/false);
+            return;
+        }
+    });
+
     // Other player level-up callback — trigger 3D effect + chat notification
     gameHandler->setOtherPlayerLevelUpCallback([this](uint64_t guid, uint32_t newLevel) {
         if (!gameHandler || !renderer) return;

src/game/game_handler.cpp

@@ -1174,6 +1174,7 @@ void GameHandler::handlePacket(network::Packet& packet) {
         if (packet.getSize() - packet.getReadPos() == 4) {
             uint32_t soundId = packet.readUInt32();
             LOG_INFO("SMSG_PLAY_MUSIC (0x0103 alias): soundId=", soundId);
+            if (playMusicCallback_) playMusicCallback_(soundId);
             return;
         }
     } else if (opcode == 0x0480) {
@@ -4496,8 +4497,8 @@ void GameHandler::handlePacket(network::Packet& packet) {
         // ---- Play music (WotLK standard opcode) ----
         case Opcode::SMSG_PLAY_MUSIC: {
             if (packet.getSize() - packet.getReadPos() >= 4) {
-                /*uint32_t soundId =*/ packet.readUInt32();
-                // TODO: hook into music manager when in-world music is reworked
+                uint32_t soundId = packet.readUInt32();
+                if (playMusicCallback_) playMusicCallback_(soundId);
             }
             break;
         }