Add iOS 27 remote media session and system player extension

RemoteShared/SystemPlayerAttributes.swift

@@ -0,0 +1,29 @@
+import Foundation
+import NowPlaying
+
+@available(iOS 27.0, *)
+struct SystemPlayerAttributes: RemoteMediaSessionAttributes {
+    let id: String
+    var title: String
+    var artist: String
+    var source: String
+    var artworkID: String?
+    var playing: Bool
+    var rate: Double
+    var position: Double
+    var duration: Double
+    var timestamp: Date
+    var capabilities: Capabilities
+    var volume: Double?
+    var hasSession: Bool
+
+    init(id: String, state: MediaState, now: Date = Date()) {
+        self.id = id
+        title = String(state.title.prefix(256)); artist = String(state.artist.prefix(256))
+        source = String(state.source.prefix(128)); artworkID = state.artworkId
+        playing = state.playbackStatus == "Playing"; rate = state.playbackRate
+        position = max(0, state.position(elapsed: 0) - state.startSeconds)
+        duration = max(0, state.endSeconds - state.startSeconds)
+        timestamp = now; capabilities = state.capabilities; volume = state.volume; hasSession = state.hasSession
+    }
+}

RemoteShared/SystemPlayerCredentials.swift

@@ -0,0 +1,42 @@
+import Foundation
+import Security
+
+enum SystemPlayerCredentials {
+    private static func query(_ id: String) throws -> [String: Any] {
+        guard let group = Bundle.main.object(forInfoDictionaryKey: "MusicBridgeSharedKeychainGroup") as? String,
+              !group.isEmpty, !group.contains("$(") else {
+            throw BridgeError.message("Подпись приложения не настроила общий Keychain для системного пульта.")
+        }
+        return [kSecClass as String: kSecClassGenericPassword, kSecAttrService as String: "MusicBridge.system-player.v1",
+                kSecAttrAccount as String: id, kSecAttrAccessGroup as String: group]
+    }
+
+    static func save(_ connection: Connection, id: String) throws {
+        let query = try query(id)
+        let values: [String: Any] = [kSecValueData as String: try JSONEncoder().encode(connection),
+                                    kSecAttrAccessible as String: kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly]
+        var status = SecItemUpdate(query as CFDictionary, values as CFDictionary)
+        if status == errSecItemNotFound { status = SecItemAdd(query.merging(values) { _, v in v } as CFDictionary, nil) }
+        guard status == errSecSuccess else { throw failure(status) }
+    }
+
+    static func load(_ id: String) throws -> Connection {
+        var query = try query(id)
+        query[kSecReturnData as String] = true; query[kSecMatchLimit as String] = kSecMatchLimitOne
+        var item: CFTypeRef?
+        let status = SecItemCopyMatching(query as CFDictionary, &item)
+        guard status == errSecSuccess, let data = item as? Data else { throw failure(status) }
+        let saved = try JSONDecoder().decode(Connection.self, from: data)
+        guard let token = saved.token, Connection.isFingerprint(token) else { throw BridgeError.unauthorized }
+        return try Connection(endpoint: saved.endpoint.absoluteString, fingerprint: saved.fingerprint, token: token)
+    }
+
+    static func delete(_ id: String) throws {
+        let status = SecItemDelete(try query(id) as CFDictionary)
+        guard status == errSecSuccess || status == errSecItemNotFound else { throw failure(status) }
+    }
+
+    private static func failure(_ status: OSStatus) -> BridgeError {
+        .message("Системный пульт не получил доступ к Keychain (\(status)). Проверьте подпись приложения и расширения; обычный плеер остаётся доступен.")
+    }
+}

RemoteShared/SystemPlayerTransport.swift

@@ -0,0 +1,56 @@
+import Foundation
+
+enum SystemPlayerAction { case play, pause, next, previous, seek, volume }
+
+@MainActor
+final class SystemPlayerTransport {
+    private var busy = false
+
+    func send(_ action: SystemPlayerAction, value: Double? = nil, sessionID: String) async throws -> MediaState {
+        guard !busy else { throw BridgeError.message("Предыдущая команда ещё выполняется.") }
+        busy = true
+        defer { busy = false }
+        let saved = try SystemPlayerCredentials.load(sessionID)
+        let client = BridgeClient(saved, timeout: 5)
+        defer { client.close() }
+        return try await Self.execute(action, value: value, client: client) {
+            let current = try SystemPlayerCredentials.load(sessionID)
+            guard current.endpoint == saved.endpoint, current.fingerprint == saved.fingerprint, current.token == saved.token else {
+                throw BridgeError.unauthorized
+            }
+        }
+    }
+
+    static func execute(_ action: SystemPlayerAction, value: Double? = nil, client: BridgeClient,
+                        validate: () throws -> Void = {}) async throws -> MediaState {
+        let state = try await client.state()
+        try validate()
+        let command = try command(action, value: value, state: state)
+        do { try await client.command(command) }
+        catch {
+            if error is URLError { throw BridgeError.message("Результат команды неизвестен. Откройте плеер перед повтором.") }
+            throw error
+        }
+        do { return try await client.state() }
+        catch {
+            if case BridgeError.unauthorized = error { throw error }
+            throw BridgeError.message("Команда выполнена, но новый трек не получен. Откройте приложение для обновления.")
+        }
+    }
+
+    static func command(_ action: SystemPlayerAction, value: Double?, state: MediaState) throws -> Command {
+        switch action {
+        case .play where state.hasSession && state.capabilities.play: return Command(type: "play", value: nil)
+        case .pause where state.hasSession && state.capabilities.pause: return Command(type: "pause", value: nil)
+        case .next where state.hasSession && state.capabilities.next: return Command(type: "next", value: nil)
+        case .previous where state.hasSession && state.capabilities.previous: return Command(type: "previous", value: nil)
+        case .seek where state.hasSession && state.capabilities.seek && state.maxSeekSeconds > state.minSeekSeconds:
+            guard let value, value.isFinite else { throw BridgeError.message("Некорректная позиция трека.") }
+            return Command(type: "seek", value: min(state.maxSeekSeconds, max(state.minSeekSeconds, state.startSeconds + value)))
+        case .volume where state.volume != nil:
+            guard let value, value.isFinite else { throw BridgeError.message("Некорректная громкость.") }
+            return Command(type: "volume", value: min(1, max(0, value)))
+        default: throw BridgeError.message("Плеер на ПК не поддерживает эту команду.")
+        }
+    }
+}