feat: media search, choices, library management (Phase 6)

Sources/Media/MediaAPI.swift

@@ -87,6 +87,7 @@ struct MediaLibrary: Decodable, Equatable {
 
 struct MediaSearchResult: Decodable, Equatable {
     let videoID: String?
+    let trackID: String?
     let title: String?
     let channel: String?
     let duration: Double?
@@ -95,6 +96,7 @@ struct MediaSearchResult: Decodable, Equatable {
     enum CodingKeys: String, CodingKey {
         case title, channel, duration
         case videoID = "video_id"
+        case trackID = "track_id"
         case inLibrary = "in_library"
     }
 }