fix(chat): dedupe duplicate assistant bubbles and align continuation bubbles

src/OpenClaw.Chat/ChatTimelineReducer.cs

@@ -189,20 +189,37 @@ static ChatTimelineState UpsertAssistant(ChatTimelineState state, string text, b
             }
         }
 
-        if (replace && reconcilePrevious && state.Entries.Count > 0)
+        // A final ChatMessageEvent that arrives without an ActiveAssistantId
+        // must, in certain cases, reconcile into the most recent Assistant
+        // entry instead of creating a duplicate bubble:
+        //
+        //  • `reconcilePrevious` flag: explicit opt-in from the provider,
+        //    used when the gateway emits the final message AFTER tool entries
+        //    have been appended (text → tool → tool output → final text). The
+        //    flag lets the reducer collapse the streaming preview into the
+        //    final text even though the immediate last entry is a ToolCall.
+        //
+        //  • Identical-text safety net: if the most recent Assistant entry
+        //    (within the same turn — i.e. before any User boundary) has
+        //    byte-equal text to the incoming message, collapse them
+        //    regardless of any flag. This catches duplicate ChatMessageEvent
+        //    emissions from the gateway (see the duplicate-bubble screenshot
+        //    bug where the same final text was rendered twice in a row).
+        if (replace && state.Entries.Count > 0)
         {
             // Scan backward for the most recent Assistant entry — not just
-            // the very last one. The gateway can emit a final message
-            // event AFTER tool entries have been appended (text → tool →
-            // tool output → final text), in which case the immediate last
-            // entry is a ToolCall. Without this scan, the final message
-            // would create a brand-new assistant entry that duplicates
-            // the streaming text the user already saw before the tool ran.
+            // the very last one (see reasons above).
             for (var li = state.Entries.Count - 1; li >= 0; li--)
             {
                 var candidate = state.Entries[li];
                 if (candidate.Kind == ChatTimelineItemKind.Assistant)
                 {
+                    var shouldMerge =
+                        reconcilePrevious
+                        || string.Equals(candidate.Text, text, StringComparison.Ordinal);
+                    if (!shouldMerge)
+                        break;
+
                     return state with
                     {
                         Entries = state.Entries.SetItem(li, candidate with

src/OpenClaw.Tray.WinUI/Chat/OpenClawChatTimeline.cs

@@ -1061,12 +1061,14 @@ Element RenderAssistantEntry(ChatTimelineItem entry, bool startsBurst, bool ends
                 return Empty();
 
             // Avatar shown only on the FIRST entry of a contiguous agent-side
-            // run. Continuation entries get no spacer — they align flush with
-            // the tool burst cards above (which also sit at the left inset),
-            // so the agent column reads as a single vertical edge.
-            Element leftSlot = !showAssistAvatar || !showAvatar
+            // run. Continuation entries reserve a 36×36 spacer so the bubble's
+            // left edge stays aligned with the first entry (matches the user
+            // burst path above and the tool burst path below).
+            Element leftSlot = !showAssistAvatar
                 ? Empty()
-                : AssistantAvatar().VAlign(VerticalAlignment.Top);
+                : (showAvatar
+                    ? AssistantAvatar().VAlign(VerticalAlignment.Top)
+                    : Border(Empty()).Size(36, 36));
 
             // Assistant bubble — subtle gray with primary text. Radius/Padding
             // come from ChatExplorationState (BubbleCornerRadius + PaddingDensity).
@@ -1103,7 +1105,7 @@ Element RenderAssistantEntry(ChatTimelineItem entry, bool startsBurst, bool ends
             var bubbleRow = Grid(
                 [GridSize.Auto, GridSize.Star()],
                 [GridSize.Auto],
-                leftSlot.Grid(row: 0, column: 0).Margin(0, 0, showAssistAvatar && showAvatar ? bubbleSideMargin : 0, 0),
+                leftSlot.Grid(row: 0, column: 0).Margin(0, 0, showAssistAvatar ? bubbleSideMargin : 0, 0),
                 card.HAlign(HorizontalAlignment.Left).Grid(row: 0, column: 1)
             ).HAlign(HorizontalAlignment.Stretch);
 
@@ -1117,7 +1119,7 @@ Element RenderAssistantEntry(ChatTimelineItem entry, bool startsBurst, bool ends
                     entryMeta?.InputTokens, entryMeta?.OutputTokens,
                     entryMeta?.ResponseTokens, entryMeta?.ContextPercent,
                     chatStampFg, entry.Id, entry.Text ?? "");
-                var leftInset = (showAssistAvatar && showAvatar) ? (36 + bubbleSideMargin) : 0;
+                var leftInset = showAssistAvatar ? (36 + bubbleSideMargin) : 0;
                 leftInset += (int)bubblePadding.Left;
                 footer = footer.Margin(leftInset, 2, 0, 0);
             }
@@ -1913,7 +1915,7 @@ string Truncate(string s, int max)
                 var burstRow = Grid(
                     [GridSize.Auto, GridSize.Star()],
                     [GridSize.Auto],
-                    leftSlot.Grid(row: 0, column: 0).Margin(0, 0, showAssistAvatar && showAvatar ? bubbleSideMargin : 0, 0),
+                    leftSlot.Grid(row: 0, column: 0).Margin(0, 0, showAssistAvatar ? bubbleSideMargin : 0, 0),
                     listCard.HAlign(HorizontalAlignment.Left).Grid(row: 0, column: 1)
                 ).HAlign(HorizontalAlignment.Stretch);
 

tests/OpenClaw.Tray.Tests/ChatTimelineReducerTests.cs

@@ -68,6 +68,64 @@ public void DuplicateFinalAssistant_DoesNotCreateSecondEntry()
         Assert.Equal("final", updated.Entries[0].Text);
     }
 
+    [Fact]
+    public void DuplicateFinalAssistant_IdenticalText_DedupesWithoutReconcileFlag()
+    {
+        // Reproduces the duplicate-bubble screenshot bug: gateway re-emits
+        // the exact same final message after a turn end without setting the
+        // ReconcilePrevious flag. The reducer must collapse identical-text
+        // duplicates as a safety net so the UI doesn't render the same
+        // assistant text twice in a row.
+        var state = ChatTimelineReducer.Apply(
+            ChatTimelineState.Initial(),
+            new ChatMessageEvent("I don't see a pending approval."));
+        state = ChatTimelineReducer.Apply(state, new ChatTurnEndEvent());
+        Assert.False(state.TurnActive);
+
+        var updated = ChatTimelineReducer.Apply(
+            state,
+            new ChatMessageEvent("I don't see a pending approval."));
+
+        Assert.Single(updated.Entries);
+        Assert.Equal("I don't see a pending approval.", updated.Entries[0].Text);
+    }
+
+    [Fact]
+    public void DuplicateFinalAssistant_DoesNotReactivatePreviousAssistant()
+    {
+        var state = ChatTimelineReducer.Apply(
+            ChatTimelineState.Initial(),
+            new ChatMessageEvent("previous"));
+        state = ChatTimelineReducer.Apply(state, new ChatTurnEndEvent());
+        state = ChatTimelineReducer.Apply(state, new ChatMessageEvent("previous"));
+        state = ChatTimelineReducer.Apply(state, new ChatUserMessageEvent("next request"));
+
+        var updated = ChatTimelineReducer.Apply(state, new ChatMessageDeltaEvent("next response"));
+
+        Assert.Equal(3, updated.Entries.Count);
+        Assert.Equal("previous", updated.Entries[0].Text);
+        Assert.Equal(ChatTimelineItemKind.User, updated.Entries[1].Kind);
+        Assert.Equal("next response", updated.Entries[2].Text);
+    }
+
+    [Fact]
+    public void SubsequentAssistant_DifferentText_AfterTurnEnd_CreatesNewEntry()
+    {
+        // Guard against over-aggressive dedupe: a genuinely new assistant
+        // message in a later turn (different text, no reconcile flag, turn
+        // already ended) must NOT be merged into the previous entry.
+        var state = ChatTimelineReducer.Apply(
+            ChatTimelineState.Initial(),
+            new ChatMessageEvent("first"));
+        state = ChatTimelineReducer.Apply(state, new ChatTurnEndEvent());
+
+        var updated = ChatTimelineReducer.Apply(state, new ChatMessageEvent("second"));
+
+        Assert.Equal(2, updated.Entries.Count);
+        Assert.Equal("first", updated.Entries[0].Text);
+        Assert.Equal("second", updated.Entries[1].Text);
+    }
+
     [Fact]
     public void AddLocalUser_CapsTrackedNonces()
     {