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,

internal/httpapi/sse.go

@@ -59,6 +59,11 @@ func (s *Server) handleEvents(w http.ResponseWriter, r *http.Request) {
 
 	slog.Debug("sse connected", "user", claims.UserID, "device", deviceName)
 
+	// Re-deliver any still-PENDING transfers addressed to this device (e.g. an offline iOS device
+	// just woken by an incoming-transfer push), so it arms its P2P answerer for the waiting
+	// sender's offer. SendTo buffers into this client's channel, drained by the loop below.
+	s.transfers.RedeliverPendingTo(r.Context(), claims.UserID, deviceName)
+
 	ping := time.NewTicker(keepaliveInterval)
 	defer ping.Stop()
 

internal/httpapi/transfer.go

@@ -20,6 +20,10 @@ type initReq struct {
 
 type initResp struct {
 	SessionID string `json:"session_id"`
+	// ReceiverOnline is false when the receiver had no live SSE at init time (a wake push was
+	// sent). The sender uses it to wait for the receiver to come online before offering, rather
+	// than immediately failing/relaying to an absent peer.
+	ReceiverOnline bool `json:"receiver_online"`
 }
 
 func (s *Server) handleTransferInit(w http.ResponseWriter, r *http.Request) {
@@ -32,7 +36,7 @@ func (s *Server) handleTransferInit(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	id, err := s.transfers.Init(r.Context(), transfer.InitParams{
+	id, receiverOnline, err := s.transfers.Init(r.Context(), transfer.InitParams{
 		UserID:       claims.UserID,
 		SenderName:   sender,
 		ReceiverName: req.ReceiverName,
@@ -44,7 +48,7 @@ func (s *Server) handleTransferInit(w http.ResponseWriter, r *http.Request) {
 		writeJSON(w, http.StatusBadRequest, map[string]string{"error": err.Error()})
 		return
 	}
-	writeJSON(w, http.StatusOK, initResp{SessionID: id})
+	writeJSON(w, http.StatusOK, initResp{SessionID: id, ReceiverOnline: receiverOnline})
 }
 
 // handleTransferTransition is the shared body for accept / cancel / fallback /

internal/transfer/service.go

@@ -6,6 +6,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+	"log/slog"
 	"time"
 
 	"commilitia.net/cdrop/internal/apns"
@@ -93,17 +94,20 @@ type InitParams struct {
 // Init creates a new PENDING session and pushes transfer:incoming to the receiver.
 // Returns the new session ID. Receiver offline does not fail Init — the receiver
 // will see the session next time it connects via /api/devices or a fresh init.
-func (s *Service) Init(ctx context.Context, p InitParams) (string, error) {
+// Init returns (sessionID, receiverOnline, error). receiverOnline is whether the receiver had a
+// live SSE at init time — false means the receiver is offline and was sent a wake push, so the
+// sender should wait for it to come online before offering (rather than fail immediately).
+func (s *Service) Init(ctx context.Context, p InitParams) (string, bool, error) {
 	if p.SenderName == "" || p.ReceiverName == "" || p.FileName == "" {
-		return "", errors.New("init: sender_name, receiver_name, file_name required")
+		return "", false, errors.New("init: sender_name, receiver_name, file_name required")
 	}
 	if p.SenderName == p.ReceiverName {
-		return "", errors.New("init: sender and receiver must differ")
+		return "", false, errors.New("init: sender and receiver must differ")
 	}
 	// brief §2 explicitly says "不限文件大小"; 0-byte is legal (empty file
 	// transfer still needs control frames). Negatives are nonsense.
 	if p.FileSize < 0 {
-		return "", errors.New("init: file_size cannot be negative")
+		return "", false, errors.New("init: file_size cannot be negative")
 	}
 
 	id := s.newID()
@@ -125,7 +129,7 @@ func (s *Service) Init(ctx context.Context, p InitParams) (string, error) {
 		FileSha256:   sha,
 		CreatedAt:    createdAt,
 	}); err != nil {
-		return "", fmt.Errorf("create session: %w", err)
+		return "", false, fmt.Errorf("create session: %w", err)
 	}
 
 	view := SessionView{
@@ -162,7 +166,51 @@ func (s *Service) Init(ctx context.Context, p InitParams) (string, error) {
 		}
 	}
 
-	return id, nil
+	return id, delivered, nil
+}
+
+// pendingTransferWindowSec bounds how far back RedeliverPendingTo looks: a transfer older than
+// this (the sender's wait window plus margin) the sender has long since given up on.
+const pendingTransferWindowSec = 180
+
+// RedeliverPendingTo re-sends transfer:incoming for the receiver's still-PENDING sessions when it
+// (re)connects — e.g. an iOS device that was offline at Init and is now woken by the incoming
+// push. Without this the woken receiver never arms its P2P answerer, so the waiting sender's offer
+// would be dropped (p2pHandleSignal ignores a signal from an unknown peer). Best-effort, bounded
+// to recent sessions; called from the SSE handler right after a device connects.
+func (s *Service) RedeliverPendingTo(ctx context.Context, userID, deviceName string) {
+	if deviceName == "" {
+		return
+	}
+	rows, err := s.queries.ListPendingTransfersByReceiver(ctx, db.ListPendingTransfersByReceiverParams{
+		UserID:       userID,
+		ReceiverName: deviceName,
+		CreatedAt:    s.now().Unix() - pendingTransferWindowSec,
+	})
+	if err != nil {
+		slog.Error("redeliver pending transfers failed", "err", err, "user", userID, "device", deviceName)
+		return
+	}
+	for _, row := range rows {
+		sha := ""
+		if row.FileSha256 != nil {
+			sha = *row.FileSha256
+		}
+		view := SessionView{
+			ID:         row.ID,
+			SenderName: row.SenderName,
+			FileName:   row.FileName,
+			FileSize:   row.FileSize,
+			FileSHA256: sha,
+		}
+		s.hub.SendTo(userID, deviceName, hub.Event{
+			Type: "transfer:incoming",
+			Data: map[string]any{
+				"session":     view,
+				"auto_accept": row.FileSize <= AutoAcceptThreshold,
+			},
+		})
+	}
 }
 
 // Transition validates and applies a state change, then broadcasts transfer:state

internal/transfer/service_test.go

@@ -83,7 +83,7 @@ func newTestServiceWithRelay(t *testing.T, r RelayController) *Service {
 
 func TestInit_AllowsZeroByteFile(t *testing.T) {
 	svc := newTestService(t)
-	if _, err := svc.Init(context.Background(), InitParams{
+	if _, _, err := svc.Init(context.Background(), InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "empty.txt", FileSize: 0,
 	}); err != nil {
@@ -93,7 +93,7 @@ func TestInit_AllowsZeroByteFile(t *testing.T) {
 
 func TestInit_PersistsPending(t *testing.T) {
 	svc := newTestService(t)
-	id, err := svc.Init(context.Background(), InitParams{
+	id, _, err := svc.Init(context.Background(), InitParams{
 		UserID:       "alice",
 		SenderName:   "tab-1",
 		ReceiverName: "tab-2",
@@ -129,7 +129,7 @@ func TestInit_RejectsBadInput(t *testing.T) {
 		{UserID: "u", SenderName: "s", ReceiverName: "r", FileName: "f", FileSize: -1},
 	}
 	for i, p := range bad {
-		if _, err := svc.Init(context.Background(), p); err == nil {
+		if _, _, err := svc.Init(context.Background(), p); err == nil {
 			t.Errorf("case %d should error: %+v", i, p)
 		}
 	}
@@ -138,7 +138,7 @@ func TestInit_RejectsBadInput(t *testing.T) {
 func TestTransition_HappyPath_PendingToDone(t *testing.T) {
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, err := svc.Init(ctx, InitParams{
+	id, _, err := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 1024,
 	})
@@ -173,7 +173,7 @@ func TestTransition_HappyPath_PendingToDone(t *testing.T) {
 func TestTransition_FallbackToRelayThenDone(t *testing.T) {
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -197,7 +197,7 @@ func TestTransition_RegistersRelayOnFallback(t *testing.T) {
 	fr := &fakeRelay{}
 	svc := newTestServiceWithRelay(t, fr)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "laptop", ReceiverName: "phone",
 		FileName: "f", FileSize: 10,
 	})
@@ -222,7 +222,7 @@ func TestTransition_RelayFullSurfacesUnavailable(t *testing.T) {
 	fr := &fakeRelay{registerErr: errors.New("too many")}
 	svc := newTestServiceWithRelay(t, fr)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -242,7 +242,7 @@ func TestTransition_RelayFullSurfacesUnavailable(t *testing.T) {
 func TestTransition_RejectsInvalidJump(t *testing.T) {
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -256,7 +256,7 @@ func TestTransition_PendingToActiveAllowed(t *testing.T) {
 	// Race tolerance: sender may call /p2p before receiver's /accept commits.
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -269,7 +269,7 @@ func TestTransition_AcceptedToDoneAllowed(t *testing.T) {
 	// Race tolerance: receiver may finish receiving (call /done) before /p2p ever fired.
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -284,7 +284,7 @@ func TestTransition_AcceptedToDoneAllowed(t *testing.T) {
 func TestTransition_RejectsForeignUser(t *testing.T) {
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "alice", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -307,7 +307,7 @@ func TestExpirePending_CancelsOldSessions(t *testing.T) {
 	old := time.Date(2026, 1, 1, 0, 0, 0, 0, time.UTC)
 	svc.now = func() time.Time { return old }
 
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})
@@ -333,7 +333,7 @@ func TestExpirePending_CancelsOldSessions(t *testing.T) {
 func TestExpirePending_LeavesFreshAlone(t *testing.T) {
 	svc := newTestService(t)
 	ctx := context.Background()
-	id, _ := svc.Init(ctx, InitParams{
+	id, _, _ := svc.Init(ctx, InitParams{
 		UserID: "u", SenderName: "s", ReceiverName: "r",
 		FileName: "f", FileSize: 10,
 	})

ios/CDrop/Sources/Engine/EngineController.swift

@@ -334,10 +334,25 @@ final class EngineController: NSObject
         return files.first { $0.lastPathComponent.hasPrefix(base) }
     }
 
-    // 可发送目标：在线、且非本机（不发给自己）。发送 / 转发两处入口共用此过滤。
+    // 可发送目标：在线设备 + 离线但可唤醒（iOS，有 APNs）的设备，且非本机。给离线可唤醒设备发送时，
+    // 后端推送唤醒它、发送端等其回前台 / 上线后再发起实时传输（见 web transfer.ts waitForPeerThenBegin）。
     func sendableDevices() -> [DeviceItem]
     {
-        return devices.filter { $0.online && $0.name != deviceName }
+        return devices.filter { $0.name != deviceName && ($0.online || Self.isWakeable($0)) }
+    }
+
+    // 离线但可经推送唤醒（目前＝iOS App）：可作为传输目标。
+    static func isWakeable(_ dev: DeviceItem) -> Bool
+    {
+        if dev.online { return false }
+        let k = dev.type.lowercased()
+        return k.contains("ios") || k.contains("iphone") || k.contains("ipad")
+    }
+
+    // 发送选择器里的设备标签：可唤醒（离线）设备附「可唤醒」提示，区别于在线设备。
+    func sendLabel(_ dev: DeviceItem) -> String
+    {
+        return Self.isWakeable(dev) ? "\(dev.name) · \(t("home.device.wakeable"))" : dev.name
     }
 
     // 剪贴板上行：读本机 UIPasteboard 文本交引擎上传云剪贴板（用户手势触发，前台读取合规）。

ios/CDrop/Sources/Resources/i18n/en-US.json

@@ -25,6 +25,7 @@
   "nav.themeToggle": "Toggle theme",
   "home.greeting": "Hello, {{name}}",
   "home.deviceList.title": "Devices",
+  "home.device.wakeable": "Wakeable",
   "home.deviceList.onlineSuffix": "({{count}} online)",
   "home.deviceList.showOffline": "Show offline ({{count}})",
   "home.deviceList.hideOffline": "Hide offline",
@@ -256,6 +257,8 @@
   "transfer.mode.relay": "Relay",
   "transfer.phase.initializing": "Initializing…",
   "transfer.phase.waiting_accept": "Waiting for the other side to accept…",
+  "transfer.phase.waiting_peer": "Waiting for the device to come online…",
+  "transfer.phase.peer_offline": "Device didn't come online",
   "transfer.phase.ice_gathering": "Gathering network candidates…",
   "transfer.phase.ice_checking": "Establishing direct tunnel…",
   "transfer.phase.ice_connected": "Tunnel established",

ios/CDrop/Sources/Resources/i18n/zh-CN.json

@@ -25,6 +25,7 @@
   "nav.themeToggle": "切换主题",
   "home.greeting": "你好，{{name}}",
   "home.deviceList.title": "设备",
+  "home.device.wakeable": "可唤醒",
   "home.deviceList.onlineSuffix": "（{{count}} 台在线）",
   "home.deviceList.showOffline": "显示离线设备（{{count}}）",
   "home.deviceList.hideOffline": "隐藏离线设备",
@@ -256,6 +257,8 @@
   "transfer.mode.relay": "中继",
   "transfer.phase.initializing": "正在初始化…",
   "transfer.phase.waiting_accept": "等待对端接受…",
+  "transfer.phase.waiting_peer": "等待对端上线…",
+  "transfer.phase.peer_offline": "对端未上线",
   "transfer.phase.ice_gathering": "收集网络候选…",
   "transfer.phase.ice_checking": "建立直连通道…",
   "transfer.phase.ice_connected": "通道已连接",

ios/CDrop/Sources/Resources/i18n/zh-TW.json

@@ -25,6 +25,7 @@
   "nav.themeToggle": "切換主題",
   "home.greeting": "你好，{{name}}",
   "home.deviceList.title": "裝置",
+  "home.device.wakeable": "可喚醒",
   "home.deviceList.onlineSuffix": "（{{count}} 部線上）",
   "home.deviceList.showOffline": "顯示離線裝置（{{count}}）",
   "home.deviceList.hideOffline": "隱藏離線裝置",
@@ -256,6 +257,8 @@
   "transfer.mode.relay": "中繼",
   "transfer.phase.initializing": "正在初始化…",
   "transfer.phase.waiting_accept": "等待對端接受…",
+  "transfer.phase.waiting_peer": "等待對端上線…",
+  "transfer.phase.peer_offline": "對端未上線",
   "transfer.phase.ice_gathering": "收集網路候選…",
   "transfer.phase.ice_checking": "建立直連通道…",
   "transfer.phase.ice_connected": "通道已連線",

ios/CDrop/Sources/RootView.swift

@@ -89,7 +89,7 @@ struct RootView: View
         {
             ForEach(engine.sendableDevices())
             { dev in
-                Button(dev.name) { engine.sendShares(to: dev.name) }
+                Button(engine.sendLabel(dev)) { engine.sendShares(to: dev.name) }
             }
             Button(t("common.cancel"), role: .cancel) { engine.dismissShares() }
         }
@@ -183,7 +183,7 @@ struct TransferListView: View
         {
             ForEach(sendableDevices)
             { dev in
-                Button(dev.name) { startSend(to: dev.name) }
+                Button(engine.sendLabel(dev)) { startSend(to: dev.name) }
             }
             Button(t("common.cancel"), role: .cancel) { }
         }
@@ -777,7 +777,7 @@ struct ReceivedFilesView: View
         {
             ForEach(engine.sendableDevices())
             { dev in
-                Button(dev.name) { send(to: dev.name) }
+                Button(engine.sendLabel(dev)) { send(to: dev.name) }
             }
             Button(t("common.cancel"), role: .cancel) { }
         }

web/src/features/devices/DeviceStrip.tsx

@@ -30,7 +30,7 @@ export function DeviceStrip(props: DeviceStripProps)
         [ devices, selfDeviceName ],
     );
     const visible = useMemo(
-        () => (showOffline ? peers : peers.filter((d) => d.online)),
+        () => (showOffline ? peers : peers.filter((d) => d.online || isWakeable(d))),
         [ peers, showOffline ],
     );
     const onlineCount  = peers.filter((d) => d.online).length;
@@ -103,7 +103,9 @@ function DevicePort(props: DevicePortProps)
 {
     const { device, selected, onClick, onDropFile } = props;
     const [ dragOver, setDragOver ] = useState(false);
-    const disabled = !device.online;
+    // 离线但可唤醒（iOS）的设备仍可选作目标：发送时后端推送唤醒、发送端等其上线再传。
+    const wakeable = isWakeable(device);
+    const disabled = !device.online && !wakeable;
 
     const handleDragOver = (e: DragEvent<HTMLButtonElement>) =>
     {
@@ -154,6 +156,8 @@ function DevicePort(props: DevicePortProps)
                         <DynText>
                             {device.online
                                 ? t("settings.online")
+                                : wakeable
+                                    ? t("home.device.wakeable")
                                     : t("settings.lastSeen", { time: formatRelative(device.lastSeen) })}
                         </DynText>
                     </span>
@@ -164,6 +168,15 @@ function DevicePort(props: DevicePortProps)
     );
 }
 
+// isWakeable：离线但可经推送唤醒的设备（目前＝iOS App，有 APNs）。可作为传输目标——发送时后端推送
+// 唤醒它，发送端等其回前台 / 上线后再发起实时传输（见 transfer.ts waitForPeerThenBegin）。
+function isWakeable(d: DeviceInfo): boolean
+{
+    if (d.online) { return false; }
+    const k = d.type.toLowerCase();
+    return k.includes("ios") || k.includes("iphone") || k.includes("ipad");
+}
+
 // 后端目前所有 web 接入都写 type="browser"；客户端时代会扩展为 macos/windows/...
 function mapKind(type: string): DeviceKind
 {

web/src/features/transfer/transfer.ts

@@ -16,6 +16,11 @@ interface OutgoingState
     src: FileSource;
     p2p: P2PSession | null;
     fallbackTimer: number | null;
+    // waitTimer / waitUnsub back the "wait for an offline receiver to wake" path: the timeout that
+    // fails the transfer if the peer never comes online, and the presence subscription that fires
+    // P2P once it does.
+    waitTimer: number | null;
+    waitUnsub: (() => void) | null;
     abort: AbortController;
 }
 
@@ -43,7 +48,11 @@ export async function startOutgoingTransfer(
         const text = await initR.text().catch(() => initR.statusText);
         throw new Error(`initiate ${initR.status}: ${text}`);
     }
-    const { session_id: sessionId } = (await initR.json()) as { session_id: string };
+    const data = (await initR.json()) as { session_id: string; receiver_online?: boolean };
+    const sessionId = data.session_id;
+    // 接收端在 initiate 时无活 SSE（离线 / 后台 / 墓碑）：后端已发唤醒推送。发送端不立即发 P2P offer
+    // （对端尚未 arm answerer，offer 会被丢），而是等对端被唤醒上线后再发起；窗口内不上线则失败。
+    const receiverOffline = data.receiver_online === false;
 
     useAppStore.getState().upsertTransfer({
         sessionId,
@@ -53,7 +62,7 @@ export async function startOutgoingTransfer(
         state: "PENDING",
         peerName: receiverName,
         startedAt: Date.now(),
-        phase: "waiting_accept",
+        phase: receiverOffline ? "waiting_peer" : "waiting_accept",
         bytesTransferred: 0,
         lastProgressAt: Date.now(),
     });
@@ -65,10 +74,27 @@ export async function startOutgoingTransfer(
         src,
         p2p: null,
         fallbackTimer: null,
+        waitTimer: null,
+        waitUnsub: null,
         abort,
     };
     outgoing.set(sessionId, state);
 
+    if (receiverOffline) { waitForPeerThenBegin(state); }
+    else { beginP2P(state); }
+
+    return sessionId;
+}
+
+// beginP2P arms the relay-fallback watchdog and starts the P2P offer. Extracted from
+// startOutgoingTransfer so the offline-receiver path can defer it until the peer wakes.
+function beginP2P(state: OutgoingState): void
+{
+    const { sessionId, peerName, src } = state;
+    const store0 = useAppStore.getState();
+    const r0 = store0.activeTransfers[sessionId];
+    if (r0 && r0.phase === "waiting_peer") { store0.upsertTransfer({ ...r0, phase: "waiting_accept" }); }
+
     // Arm the fallback watchdog *before* any P2P work. p2pStartOutgoing is
     // intentionally synchronous: if createOffer / setLocalDescription hang
     // (e.g. injected stub during fallback testing) the timer must still fire.
@@ -88,7 +114,7 @@ export async function startOutgoingTransfer(
         }
     }, ICE_TIMEOUT_MS);
 
-    const p2p = p2pStartOutgoing(sessionId, receiverName, src);
+    const p2p = p2pStartOutgoing(sessionId, peerName, src);
     state.p2p = p2p;
 
     p2p.onState((s) =>
@@ -98,8 +124,53 @@ export async function startOutgoingTransfer(
             if (state.fallbackTimer) { clearTimeout(state.fallbackTimer); state.fallbackTimer = null; }
         }
     });
+}
 
-    return sessionId;
+// PEER_WAIT_MS bounds how long the sender waits for an offline receiver to wake + reconnect.
+const PEER_WAIT_MS = 60_000;
+// PEER_ARM_DELAY_MS gives the woken receiver a beat to arm its P2P answerer (from the backend's
+// reconnect re-delivery of transfer:incoming) before the sender's offer arrives.
+const PEER_ARM_DELAY_MS = 1_200;
+
+// waitForPeerThenBegin defers the P2P offer until an offline receiver comes online (woken by the
+// incoming-transfer push). Watches presence; on the peer appearing online it waits a beat for the
+// receiver to arm its answerer, then offers. Times out to a FAILED transfer if the peer never wakes.
+function waitForPeerThenBegin(state: OutgoingState): void
+{
+    const { sessionId, peerName } = state;
+    const peerOnline = (): boolean =>
+        useAppStore.getState().devices.some((d) => d.name === peerName && d.online);
+
+    const proceed = (): void =>
+    {
+        if (state.waitUnsub) { state.waitUnsub(); state.waitUnsub = null; }
+        if (state.waitTimer !== null) { clearTimeout(state.waitTimer); state.waitTimer = null; }
+        if (state.abort.signal.aborted) { return; }
+        window.setTimeout(() => { if (!state.abort.signal.aborted) { beginP2P(state); } }, PEER_ARM_DELAY_MS);
+    };
+
+    if (peerOnline()) { proceed(); return; }
+
+    state.waitUnsub = useAppStore.subscribe(() =>
+    {
+        if (state.abort.signal.aborted) { state.waitUnsub?.(); state.waitUnsub = null; return; }
+        if (peerOnline()) { proceed(); }
+    });
+
+    state.waitTimer = window.setTimeout(() =>
+    {
+        if (state.waitUnsub) { state.waitUnsub(); state.waitUnsub = null; }
+        state.waitTimer = null;
+        if (state.abort.signal.aborted) { return; }
+        const store = useAppStore.getState();
+        const r = store.activeTransfers[sessionId];
+        if (r && r.state === "PENDING")
+        {
+            void apiFetch(`/api/transfer/${sessionId}/cancel`, { method: "POST" }).catch(() => { /* best-effort */ });
+            store.upsertTransfer({ ...r, state: "FAILED", phase: "peer_offline" });
+        }
+        outgoing.delete(sessionId);
+    }, PEER_WAIT_MS);
 }
 
 async function triggerFallback(sessionId: string): Promise<void>
@@ -241,6 +312,8 @@ function cleanupOutgoing(sessionId: string): void
     const s = outgoing.get(sessionId);
     if (!s) { return; }
     if (s.fallbackTimer) { clearTimeout(s.fallbackTimer); }
+    if (s.waitTimer !== null) { clearTimeout(s.waitTimer); }
+    if (s.waitUnsub) { s.waitUnsub(); }
     s.abort.abort();
     outgoing.delete(sessionId);
 }

web/src/i18n/locales/en-US.ts

@@ -37,6 +37,7 @@ export const enUS: Partial<TranslationDict> = {
     // ---- home -----------------------------------------------------------
     "home.greeting": "Hello, {{name}}",
     "home.deviceList.title": "Devices",
+    "home.device.wakeable": "Wakeable",
     "home.deviceList.onlineSuffix": "({{count}} online)",
     "home.deviceList.showOffline": "Show offline ({{count}})",
     "home.deviceList.hideOffline": "Hide offline",
@@ -298,6 +299,8 @@ export const enUS: Partial<TranslationDict> = {
     // ---- client phase (real-time telemetry; tells "waiting" from "stuck") ----
     "transfer.phase.initializing":      "Initializing…",
     "transfer.phase.waiting_accept":    "Waiting for the other side to accept…",
+    "transfer.phase.waiting_peer":      "Waiting for the device to come online…",
+    "transfer.phase.peer_offline":      "Device didn't come online",
     "transfer.phase.ice_gathering":     "Gathering network candidates…",
     "transfer.phase.ice_checking":      "Establishing direct tunnel…",
     "transfer.phase.ice_connected":     "Tunnel established",

web/src/i18n/locales/zh-CN.ts

@@ -34,6 +34,7 @@ export const zhCN = {
     // ---- 主页 ------------------------------------------------------------
     "home.greeting": "你好，{{name}}",
     "home.deviceList.title": "设备",
+    "home.device.wakeable": "可唤醒",
     "home.deviceList.onlineSuffix": "（{{count}} 台在线）",
     "home.deviceList.showOffline": "显示离线设备（{{count}}）",
     "home.deviceList.hideOffline": "隐藏离线设备",
@@ -294,6 +295,8 @@ export const zhCN = {
     // ---- 客户端 phase（实时遥测，区分等待中和卡住）----------------------
     "transfer.phase.initializing":      "正在初始化…",
     "transfer.phase.waiting_accept":    "等待对端接受…",
+    "transfer.phase.waiting_peer":      "等待对端上线…",
+    "transfer.phase.peer_offline":      "对端未上线",
     "transfer.phase.ice_gathering":     "收集网络候选…",
     "transfer.phase.ice_checking":      "建立直连通道…",
     "transfer.phase.ice_connected":     "通道已连接",

web/src/i18n/locales/zh-TW.ts

@@ -38,6 +38,7 @@ export const zhTW: Partial<TranslationDict> = {
     // ---- 首頁 ------------------------------------------------------------
     "home.greeting": "你好，{{name}}",
     "home.deviceList.title": "裝置",
+    "home.device.wakeable": "可喚醒",
     "home.deviceList.onlineSuffix": "（{{count}} 部線上）",
     "home.deviceList.showOffline": "顯示離線裝置（{{count}}）",
     "home.deviceList.hideOffline": "隱藏離線裝置",
@@ -298,6 +299,8 @@ export const zhTW: Partial<TranslationDict> = {
     // ---- 客戶端 phase（即時遙測，區分等待中和卡住）---------------------
     "transfer.phase.initializing":      "正在初始化…",
     "transfer.phase.waiting_accept":    "等待對端接受…",
+    "transfer.phase.waiting_peer":      "等待對端上線…",
+    "transfer.phase.peer_offline":      "對端未上線",
     "transfer.phase.ice_gathering":     "收集網路候選…",
     "transfer.phase.ice_checking":      "建立直連通道…",
     "transfer.phase.ice_connected":     "通道已連線",

web/src/store/types.ts

@@ -38,6 +38,8 @@ export type ThemeMode = "light" | "dark" | "system";
 export type TransferPhase =
     | "initializing"        // 刚 /initiate / 收到 transfer:incoming，未起 WebRTC
     | "waiting_accept"      // sender 等 /accept，receiver 等自己 /accept 回执
+    | "waiting_peer"        // 接收端离线/后台：已推送唤醒，发送端等其上线再发起 P2P
+    | "peer_offline"        // 等待窗口内对端未上线，传输失败
     | "ice_gathering"       // RTCPeerConnection 正在收集候选
     | "ice_checking"        // 候选已交换，连通性检查中
     | "ice_connected"       // ICE 通过，DC 即将打开