Fix unread marker and room dot not clearing reliably

The 'New' unread marker in the timeline never auto-dismissed because the
dismiss timer in .task fired before the diff pipeline had computed
firstUnreadMessageId. Move the timer to an onChange handler so it starts
exactly when the marker position is first set.

The sidebar unread dot reappeared after markAsRead because applyRoomInfo
unconditionally overwrote the optimistically-cleared counts with stale
SDK values. Add an isOptimisticallyCleared flag on RoomSummary that
guards against stale overwrites until the SDK confirms zero unreads.

Fixes: #73

Assisted-By: Claude

Author: subpop

Packages/RelayInterface/Sources/RelayInterface/Models/RoomSummary.swift

@@ -105,6 +105,13 @@ public final class RoomSummary: Identifiable {
     /// cleared when the room is marked as read.
     public var hasKeywordHighlight: Bool = false
 
+    /// Whether unread counts were optimistically cleared by ``markAsRead``.
+    ///
+    /// When `true`, the room list manager should not overwrite the cleared counts
+    /// with stale SDK values. The flag is reset when the SDK itself reports zero
+    /// unread messages, confirming the server has processed the read receipt.
+    public var isOptimisticallyCleared: Bool = false
+
     /// The user's current membership state in this room.
     public var membership: RoomMembership
 

Relay/Views/Timeline/TimelineView.swift

@@ -205,27 +205,31 @@ struct TimelineView: View { // swiftlint:disable:this type_body_length
             // Fetch room members for mention autocomplete
             compose.members = await matrixService.roomMembers(roomId: roomId)
 
-            // Auto-dismiss the "New" marker after 5 seconds, then clear it
-            if viewModel.firstUnreadMessageId != nil {
-                showUnreadMarker = true
-                unreadMarkerDismissTask?.cancel()
-                unreadMarkerDismissTask = Task {
-                    try? await Task.sleep(for: .seconds(5))
-                    guard !Task.isCancelled else { return }
-                    withAnimation(.easeOut(duration: 0.4)) {
-                        showUnreadMarker = false
-                    }
-                    try? await Task.sleep(for: .milliseconds(500))
-                    guard !Task.isCancelled else { return }
-                    viewModel.firstUnreadMessageId = nil
-                }
-            }
         }
         .onDisappear {
             if !readOnly, sendTypingNotifications {
                 Task { await matrixService.sendTypingNotice(roomId: roomId, isTyping: false) }
             }
             memberRefreshTask?.cancel()
+            unreadMarkerDismissTask?.cancel()
+        }
+        .onChange(of: viewModel.firstUnreadMessageId) { oldValue, newValue in
+            // When the unread marker position is first computed (nil -> value),
+            // start a 5-second auto-dismiss timer. This avoids the race where
+            // the old .task check fired before the diff pipeline had set the ID.
+            guard oldValue == nil, newValue != nil else { return }
+            showUnreadMarker = true
+            unreadMarkerDismissTask?.cancel()
+            unreadMarkerDismissTask = Task {
+                try? await Task.sleep(for: .seconds(5))
+                guard !Task.isCancelled else { return }
+                withAnimation(.easeOut(duration: 0.4)) {
+                    showUnreadMarker = false
+                }
+                try? await Task.sleep(for: .milliseconds(500))
+                guard !Task.isCancelled else { return }
+                viewModel.firstUnreadMessageId = nil
+            }
         }
         .onChange(of: membershipEventCount) {
             guard !readOnly else { return }

RelayKit/Services/MatrixService.swift

@@ -662,10 +662,14 @@ public final class MatrixService: MatrixServiceProtocol {
 
         // Optimistically clear unread indicators so the room list updates immediately
         // rather than waiting for the server round-trip through the sync loop.
+        // The isOptimisticallyCleared flag prevents the room info listener from
+        // overwriting these zeros with stale SDK values before the server processes
+        // the read receipt.
         if let summary = rooms.first(where: { $0.id == roomId }) {
             summary.unreadMessages = 0
             summary.unreadMentions = 0
             summary.hasKeywordHighlight = false
+            summary.isOptimisticallyCleared = true
         }
 
         let receiptType: ReceiptType = sendPublicReceipt ? .read : .readPrivate

RelayKit/Services/RoomListManager.swift

@@ -437,17 +437,32 @@ private final class RoomEntry: Identifiable {
             summary.avatarURL = nil
         }
 
-        summary.unreadMessages = UInt(info.numUnreadMessages)
-        // Use the SDK's mention count as a floor; our client-side detection
-        // may have already incremented unreadMentions higher than what the
-        // SDK reports (e.g. for keyword matches). When the SDK value drops
-        // to zero (room marked as read), reset our count too.
+        // When the room was optimistically marked as read, the SDK may still
+        // report stale non-zero unread counts until the server processes the
+        // read receipt. Skip overwriting the cleared values in that case.
+        // Once the SDK itself reports zero, clear the optimistic flag.
+        let sdkUnread = UInt(info.numUnreadMessages)
         let sdkMentions = UInt(info.numUnreadMentions)
-        if sdkMentions == 0 && info.numUnreadMessages == 0 {
-            summary.unreadMentions = 0
-            summary.hasKeywordHighlight = false
-        } else if sdkMentions > summary.unreadMentions {
-            summary.unreadMentions = sdkMentions
+        if summary.isOptimisticallyCleared {
+            if sdkUnread == 0 && sdkMentions == 0 {
+                // Server confirmed — safe to clear the guard.
+                summary.isOptimisticallyCleared = false
+                summary.unreadMentions = 0
+                summary.hasKeywordHighlight = false
+            }
+            // Otherwise keep the optimistically-cleared zeros.
+        } else {
+            summary.unreadMessages = sdkUnread
+            // Use the SDK's mention count as a floor; our client-side detection
+            // may have already incremented unreadMentions higher than what the
+            // SDK reports (e.g. for keyword matches). When the SDK value drops
+            // to zero (room marked as read), reset our count too.
+            if sdkMentions == 0 && sdkUnread == 0 {
+                summary.unreadMentions = 0
+                summary.hasKeywordHighlight = false
+            } else if sdkMentions > summary.unreadMentions {
+                summary.unreadMentions = sdkMentions
+            }
         }
         summary.isDirect = info.isDirect
         summary.canonicalAlias = info.canonicalAlias