Migrate five more coordinators to narrow context protocols

ChatTransportEventCoordinator, ChatPeerIdentityCoordinator,
ChatMediaTransferCoordinator, ChatVerificationCoordinator, and
ChatLifecycleCoordinator drop their unowned ChatViewModel back-refs for
narrow @MainActor contexts (20-36 members each), reusing shared
witnesses across protocols. The two remaining raw writers of
sentReadReceipts now route through owner intent ops
(unmarkReadReceiptsSent, syncReadReceiptsForSentMessages), closing the
gaps noted in the previous commit. NoiseEncryptionService stays fully
out of the verification coordinator via installNoiseSessionCallbacks.
26 new mock-context tests.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

bitchat/ViewModels/ChatViewModel.swift

@@ -147,18 +147,18 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
     let autocompleteService: AutocompleteService
     let deduplicationService: MessageDeduplicationService  // internal for test access
     private lazy var outgoingCoordinator = ChatOutgoingCoordinator(viewModel: self)
-    private lazy var lifecycleCoordinator = ChatLifecycleCoordinator(viewModel: self)
-    private lazy var transportEventCoordinator = ChatTransportEventCoordinator(viewModel: self)
+    private lazy var lifecycleCoordinator = ChatLifecycleCoordinator(context: self)
+    private lazy var transportEventCoordinator = ChatTransportEventCoordinator(context: self)
     private lazy var peerListCoordinator = ChatPeerListCoordinator(viewModel: self)
     private lazy var messageFormatter = ChatMessageFormatter(viewModel: self)
-    lazy var peerIdentityCoordinator = ChatPeerIdentityCoordinator(viewModel: self)
+    lazy var peerIdentityCoordinator = ChatPeerIdentityCoordinator(context: self)
     lazy var deliveryCoordinator = ChatDeliveryCoordinator(context: self)
     lazy var composerCoordinator = ChatComposerCoordinator(viewModel: self)
     lazy var publicConversationCoordinator = ChatPublicConversationCoordinator(context: self)
     lazy var privateConversationCoordinator = ChatPrivateConversationCoordinator(context: self)
     lazy var nostrCoordinator = ChatNostrCoordinator(context: self)
-    lazy var mediaTransferCoordinator = ChatMediaTransferCoordinator(viewModel: self)
-    lazy var verificationCoordinator = ChatVerificationCoordinator(viewModel: self)
+    lazy var mediaTransferCoordinator = ChatMediaTransferCoordinator(context: self)
+    lazy var verificationCoordinator = ChatVerificationCoordinator(context: self)
 
     // Computed properties for compatibility
     @MainActor
@@ -453,6 +453,25 @@ final class ChatViewModel: ObservableObject, BitchatDelegate, TransportEventDele
         sentGeoDeliveryAcks.insert(messageID).inserted
     }
 
+    /// Forgets that read receipts were sent for `ids` so READ acks can be
+    /// re-sent after the peer reconnects.
+    @MainActor
+    func unmarkReadReceiptsSent(_ ids: [String]) {
+        sentReadReceipts.subtract(ids)
+    }
+
+    /// Marks read receipts as sent for own messages already delivered/read in
+    /// `peerID`'s chat, syncing the chat manager's tracking with the persisted
+    /// set. (Wraps the manager's `inout` sync so the raw set never leaks.)
+    @MainActor
+    func syncReadReceiptsForSentMessages(for peerID: PeerID) {
+        privateChatManager.syncReadReceiptsForSentMessages(
+            peerID: peerID,
+            nickname: nickname,
+            externalReceipts: &sentReadReceipts
+        )
+    }
+
     /// Drops every recorded read receipt whose message ID is no longer valid.
     /// Returns the number of receipts removed.
     @MainActor