feat: media session source and media card

app/src/main/java/top/yeij/hearth/webview/JsBridge.kt

@@ -4,6 +4,7 @@ import android.util.Log
 import top.yeij.hearth.app.AppRepository
 import top.yeij.hearth.card.Card
 import top.yeij.hearth.card.CardRepository
+import top.yeij.hearth.media.MediaSessionSource
 import top.yeij.hearth.webapp.WebApp
 import top.yeij.hearth.webapp.WebAppRepository
 
@@ -55,4 +56,18 @@ class JsBridge(
         Log.d("HearthBridge", "fetchCards: ${cards.size} cards")
         return gson.toJson(cards)
     }
+
+    // 注册媒体会话监听，回调推送给 H5（info 为 null 时推 "null"）
+    // Register media session listener; push callbacks to H5 (push "null" when info is null)
+    fun setMediaListener(source: MediaSessionSource, webView: android.webkit.WebView) {
+        source.start { info ->
+            webView.post {
+                val json = info?.toJson() ?: "null"
+                webView.evaluateJavascript(
+                    "window.HearthEvents && window.HearthEvents.mediaSessionChanged($json);",
+                    null
+                )
+            }
+        }
+    }
 }