fix: sync support private chat content protection

internal/store/memory/message_store.go

@@ -8,6 +8,7 @@ import (
 // MessageStore 是 store.MessageStore 的内存实现。
 type MessageStore struct {
 	mu                  sync.RWMutex
+	noForwardsMu        sync.Mutex
 	m                   map[int64][]domain.Message
 	nextUID             int64
 	nextBox             map[int64]int
@@ -24,6 +25,11 @@ type MessageStore struct {
 	polls *PollStore
 	// savedPins 是收藏夹子会话置顶顺序（下标即 pinned_order，越小越前）。
 	savedPins map[int64][]domain.Peer
+	// privateNoForwards is keyed by the sorted user pair. Requests are keyed by
+	// the shared logical private-message id so both local box ids resolve to one
+	// one-shot response fact.
+	privateNoForwards         map[privateNoForwardsPair]domain.PrivateNoForwardsState
+	privateNoForwardsRequests map[int64]memoryNoForwardsRequest
 }
 
 // AttachPollStore 注入共享 poll 权威（与 ChannelStore 共用同一实例）。
@@ -40,18 +46,20 @@ type readOutboxDateKey struct {
 // NewMessageStore 创建内存 MessageStore。
 func NewMessageStore(dialogs ...*DialogStore) *MessageStore {
 	s := &MessageStore{
-		m:                   make(map[int64][]domain.Message),
-		nextUID:             1,
-		nextBox:             make(map[int64]int),
-		nextPts:             make(map[int64]int),
-		readOutboxDates:     make(map[readOutboxDateKey]int),
-		privateReactions:    make(map[int64]map[int64][]domain.ChannelMessagePeerReaction),
-		savedMessageTags:    make(map[int64]map[int][]domain.MessageReaction),
-		savedTagTitles:      make(map[int64]map[string]string),
-		privateSendDedup:    make(map[privateSendDedupKey]privateSendDedupRecord),
-		loginCodeDeliveries: make(map[[32]byte]loginCodeDeliveryRecord),
-		albumGroups:         make(map[albumGroupKey]albumGroupRecord),
-		savedPins:           make(map[int64][]domain.Peer),
+		m:                         make(map[int64][]domain.Message),
+		nextUID:                   1,
+		nextBox:                   make(map[int64]int),
+		nextPts:                   make(map[int64]int),
+		readOutboxDates:           make(map[readOutboxDateKey]int),
+		privateReactions:          make(map[int64]map[int64][]domain.ChannelMessagePeerReaction),
+		savedMessageTags:          make(map[int64]map[int][]domain.MessageReaction),
+		savedTagTitles:            make(map[int64]map[string]string),
+		privateSendDedup:          make(map[privateSendDedupKey]privateSendDedupRecord),
+		loginCodeDeliveries:       make(map[[32]byte]loginCodeDeliveryRecord),
+		albumGroups:               make(map[albumGroupKey]albumGroupRecord),
+		savedPins:                 make(map[int64][]domain.Peer),
+		privateNoForwards:         make(map[privateNoForwardsPair]domain.PrivateNoForwardsState),
+		privateNoForwardsRequests: make(map[int64]memoryNoForwardsRequest),
 	}
 	if len(dialogs) > 0 {
 		s.dialogs = dialogs[0]