传输等待前台：后台 / 墓碑 iOS 可作可唤醒传输目标 + 发送端等其回前台再传

- 根因：presence 的 online 仅表示有活 SSE，故后台 / 墓碑态 iOS 被判离线、不进传输目标，使前面的后台响应（推送唤醒 + 离线队列）实际无从触发。诉求模型：离线但可唤醒的设备可选作目标；发送端推送唤醒对端、等其回前台上线后再走实时传输（非服务端暂存转发）。
- 后端：transfer.Init 返回 receiverOnline（＝SendTo delivered）；handleTransferInit 回 receiver_online。新增 ListPendingTransfersByReceiver 查询 + Service.RedeliverPendingTo——接收端重连即补发其仍 PENDING 的 transfer:incoming（窗口内），使被唤醒的 iOS 重新 arm P2P answerer（否则发送端 offer 因 p2pHandleSignal 不识未知 peer 而被丢）；sse.go handleEvents 在 hub.Connect 后调用它。
- 发送端 web/transfer.ts：startOutgoingTransfer 按 receiver_online 分流——在线即 beginP2P（原 P2P + fallback 逻辑抽出）；离线则 waitForPeerThenBegin：标 phase=waiting_peer、订阅 presence、对端上线即延 1.2s（待其 arm）再 beginP2P；60s 窗口内不上线则 cancel + FAILED phase=peer_offline。cleanupOutgoing 清理 waitTimer / waitUnsub。TransferPhase 加 waiting_peer / peer_offline + 三语 i18n。
- 目标纳入 + 标记：离线但可唤醒（type 含 ios）的设备可选作传输目标、标「可唤醒」。web DeviceStrip 加 isWakeable（纳入 visible、放开 disabled、标签）；iOS EngineController.sendableDevices 纳入 + isWakeable + sendLabel，三处发送选择器（传输 / 分享 / 收到的文件转发）改用 sendLabel。i18n 加 home.device.wakeable。
- 机制说明（留档）：content-available 静默唤醒不会让挂起的引擎重连 SSE；真正上线＝用户点推送回前台 → 引擎恢复 → SSE 重连 → 后端补发 incoming → arm → 发送端 offer。若 offer 与 arm 抢拍掉了，30s 后 relay 兜底（此时对端已在线）。可唤醒判定用类型启发式（离线 + ios），未加后端 push-sub 查询。
- 测试：service_test 适配 Init 的三返回值。

internal/db/queries/transfers.sql

@@ -21,6 +21,16 @@ SET state             = sqlc.arg('state'),
     bytes_transferred = COALESCE(sqlc.narg('bytes_transferred'), bytes_transferred)
 WHERE id = sqlc.arg('id');
 
+-- name: ListPendingTransfersByReceiver :many
+-- Still-PENDING transfers addressed to a receiver, bounded to recently created ones (the
+-- sender's wait window). Re-delivered as transfer:incoming when that receiver (re)connects -
+-- e.g. an offline iOS device just woken by the incoming-transfer push -so it arms its P2P
+-- answerer for the waiting sender's offer.
+SELECT id, sender_name, file_name, file_size, file_sha256
+FROM transfer_sessions
+WHERE user_id = ? AND receiver_name = ? AND state = 'PENDING' AND created_at > ?
+ORDER BY created_at ASC;
+
 -- name: ExpirePendingSessions :many
 UPDATE transfer_sessions
 SET state       = 'CANCELLED',

internal/db/transfers.sql.go

@@ -120,6 +120,60 @@ func (q *Queries) GetTransferSession(ctx context.Context, id string) (TransferSe
 	return i, err
 }
 
+const listPendingTransfersByReceiver = `-- name: ListPendingTransfersByReceiver :many
+SELECT id, sender_name, file_name, file_size, file_sha256
+FROM transfer_sessions
+WHERE user_id = ? AND receiver_name = ? AND state = 'PENDING' AND created_at > ?
+ORDER BY created_at ASC
+`
+
+type ListPendingTransfersByReceiverParams struct {
+	UserID       string `json:"user_id"`
+	ReceiverName string `json:"receiver_name"`
+	CreatedAt    int64  `json:"created_at"`
+}
+
+type ListPendingTransfersByReceiverRow struct {
+	ID         string  `json:"id"`
+	SenderName string  `json:"sender_name"`
+	FileName   string  `json:"file_name"`
+	FileSize   int64   `json:"file_size"`
+	FileSha256 *string `json:"file_sha256"`
+}
+
+// Still-PENDING transfers addressed to a receiver, bounded to recently created ones (the
+// sender's wait window). Re-delivered as transfer:incoming when that receiver (re)connects -
+// e.g. an offline iOS device just woken by the incoming-transfer push -so it arms its P2P
+// answerer for the waiting sender's offer.
+func (q *Queries) ListPendingTransfersByReceiver(ctx context.Context, arg ListPendingTransfersByReceiverParams) ([]ListPendingTransfersByReceiverRow, error) {
+	rows, err := q.db.QueryContext(ctx, listPendingTransfersByReceiver, arg.UserID, arg.ReceiverName, arg.CreatedAt)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var items []ListPendingTransfersByReceiverRow
+	for rows.Next() {
+		var i ListPendingTransfersByReceiverRow
+		if err := rows.Scan(
+			&i.ID,
+			&i.SenderName,
+			&i.FileName,
+			&i.FileSize,
+			&i.FileSha256,
+		); err != nil {
+			return nil, err
+		}
+		items = append(items, i)
+	}
+	if err := rows.Close(); err != nil {
+		return nil, err
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return items, nil
+}
+
 const updateTransferState = `-- name: UpdateTransferState :execrows
 UPDATE transfer_sessions
 SET state             = ?1,