feat: add stream audio broadcast support

- 添加stream音频格式的客户端播放逻辑与网络消息解析
- 新增云服务端媒体静态服务端点，重构音频处理逻辑以返回流URL替代原始音频缓冲区
- 更新所有相关业务接口适配新的流音频播放流程
- 新增API基础地址环境变量配置

station_broadcast.lua

@@ -687,7 +687,9 @@ local function playHqAudioItem(item)
 
     if controller then
         local ok, result = pcall(function()
-            if format == "wav" and type(controller.speakWavAll) == "function" then
+            if format == "stream" and type(controller.speakStreamAll) == "function" then
+                return controller.speakStreamAll(payload, CONFIG.AUDIO_VOLUME)
+            elseif format == "wav" and type(controller.speakWavAll) == "function" then
                 return controller.speakWavAll(payload, CONFIG.AUDIO_VOLUME)
             elseif type(controller.speakFileAll) == "function" then
                 return controller.speakFileAll(payload, CONFIG.AUDIO_VOLUME)
@@ -701,7 +703,9 @@ local function playHqAudioItem(item)
     if not called then
         for _, sp in ipairs(Peripherals.speakers) do
             local ok, result = pcall(function()
-                if format == "wav" and type(sp.speakWav) == "function" then
+                if format == "stream" and type(sp.speakStream) == "function" then
+                    return sp.speakStream(payload, CONFIG.AUDIO_VOLUME)
+                elseif format == "wav" and type(sp.speakWav) == "function" then
                     return sp.speakWav(payload, CONFIG.AUDIO_VOLUME)
                 elseif type(sp.speakFile) == "function" then
                     return sp.speakFile(payload, CONFIG.AUDIO_VOLUME)
@@ -769,7 +773,7 @@ end
 
 function Audio.playItem(item)
     local format = tostring(item.audioFormat or "dfpwm"):lower()
-    if format == "wav" or format == "file" then
+    if format == "wav" or format == "file" or format == "stream" then
         return playHqAudioItem(item)
     end
     return Audio.playDfpwmItem(item)
@@ -1068,6 +1072,7 @@ function Network.messageLoop()
                     end
                     local priority = tonumber(data.priority) or 0
                     local audioFormat = tostring(data.audioFormat or "dfpwm"):lower()
+                    local streamUrl = type(data.streamUrl) == "string" and data.streamUrl or nil
                     local interruptMode = tostring(data.interruptMode or "")
                     if interruptMode == "" then
                         if priority >= 2 then interruptMode = "all"
@@ -1090,7 +1095,16 @@ function Network.messageLoop()
                         audioFormat = audioFormat
                     }
                     
-                    if audioFormat == "dfpwm" then
+                    if audioFormat == "stream" and streamUrl and streamUrl ~= "" then
+                        Audio.enqueueItem({
+                            audioData = streamUrl,
+                            audioFormat = "stream",
+                            priority = priority,
+                            source = State.audioRx.source,
+                            audioId = data.audioId
+                        })
+                        State.audioRx = nil
+                    elseif audioFormat == "dfpwm" then
                         local stream = Audio.createStream()
                         State.audioRx.stream = stream
                         Audio.enqueueItem({