refactor: simplify cross-session messaging

webui/src/hooks/useNanobotStream.ts

@@ -33,7 +33,6 @@ import type {
   OutboundCliAppMention,
   OutboundMcpPresetMention,
   OutboundMedia,
-  SessionHandle,
   SessionMention,
   GoalStateWsPayload,
   MessageDeliveryStatus,
@@ -170,7 +169,6 @@ export interface SendOptions {
   cliApps?: OutboundCliAppMention[];
   mcpPresets?: OutboundMcpPresetMention[];
   sessionMentions?: SessionMention[];
-  sessionHandles?: SessionHandle[];
   quotedContext?: string;
   workspaceScope?: WorkspaceScopePayload | null;
   sideChannel?: boolean;
@@ -190,7 +188,6 @@ function eventExtendsModelActivity(ev: InboundEvent): boolean {
     ev.event === "delta"
     || ev.event === "reasoning_delta"
     || ev.event === "file_edit"
-    || ev.event === "session_message"
   ) return true;
   return ev.event === "message"
     && (ev.kind === "tool_hint" || ev.kind === "progress" || ev.kind === "reasoning");
@@ -221,31 +218,27 @@ function transitionTurnDelivery(
   return changed ? next : messages;
 }
 
-function appendLiveSessionMessage(
+function appendProjectedSessionInput(
   messages: UIMessage[],
-  event: Extract<InboundEvent, { event: "session_message" }>,
+  event: Extract<InboundEvent, { event: "user_message" }>,
 ): UIMessage[] {
-  const messageId = event.session_message?.message_id?.trim();
-  if (!messageId || event.session_message.direction !== "incoming") return messages;
+  const sessionMessage = event.provenance?.session_message;
+  const messageId = sessionMessage?.message_id?.trim();
+  if (!sessionMessage || !messageId) return messages;
   if (messages.some((message) => message.sessionMessage?.message_id === messageId)) return messages;
 
   const row: UIMessage = {
     id: `session-message:${messageId}`,
     role: "user",
     content: event.text,
-    createdAt: Number.isFinite(event.created_at_ms) ? event.created_at_ms : Date.now(),
-    sessionMessage: event.session_message,
+    createdAt: typeof event.created_at_ms === "number"
+      && Number.isFinite(event.created_at_ms)
+      ? event.created_at_ms
+      : Date.now(),
+    sessionMessage,
     ...turnFieldsFromEvent(event, "user"),
   };
-  const sameTurnIndex = event.turn_id
-    ? messages.findIndex((message) => message.turnId === event.turn_id)
-    : -1;
-  if (sameTurnIndex < 0) return [...messages, row];
-  return [
-    ...messages.slice(0, sameTurnIndex),
-    row,
-    ...messages.slice(sameTurnIndex),
-  ];
+  return [...messages, row];
 }
 
 export function useNanobotStream(
@@ -675,18 +668,6 @@ export function useNanobotStream(
     });
   }, [cancelStreamEndTimer, client]);
 
-  useEffect(() => {
-    return client.onRunStatus((updatedChatId, startedAt) => {
-      if (updatedChatId !== chatId) return;
-      // Canonical HTTP reconciliation can settle a turn before its delayed
-      // WebSocket completion frame reaches this mounted thread. The client
-      // then fences that duplicate frame, so keep the pane-local timer in
-      // sync with the client's authoritative per-chat run projection.
-      setRunStartedAt(startedAt);
-      if (startedAt !== null) setIsStreaming(true);
-    });
-  }, [chatId, client]);
-
   // Reset local state when switching chats. Do not reset on every
   // ``initialMessages`` update: a brand-new chat can receive an empty/404
   // history response after the optimistic first message has already rendered.
@@ -752,6 +733,13 @@ export function useNanobotStream(
       }
       if (ev.event === "message_accepted") return;
       if (ev.event === "user_message") {
+        if (ev.provenance?.session_message) {
+          flushPendingStreamEvents({ closeAnswerSegment: true });
+          clearActivitySegment();
+          setIsStreaming(true);
+          setMessages((prev) => appendProjectedSessionInput(prev, ev));
+          return;
+        }
         setMessages((prev) => {
           if (ev.turn_id && prev.some((message) => (
             message.role === "user" && message.turnId === ev.turn_id
@@ -766,7 +754,10 @@ export function useNanobotStream(
               turnPhase: "user",
               turnSeq: 0,
               deliveryStatus: "accepted",
-              createdAt: Date.now(),
+              createdAt: typeof ev.created_at_ms === "number"
+                && Number.isFinite(ev.created_at_ms)
+                ? ev.created_at_ms
+                : Date.now(),
               ...(ev.media_urls?.length ? { media: ev.media_urls } : {}),
               ...(ev.cli_apps?.length ? { cliApps: ev.cli_apps } : {}),
               ...(ev.mcp_presets?.length ? { mcpPresets: ev.mcp_presets } : {}),
@@ -844,20 +835,12 @@ export function useNanobotStream(
 
       const shouldCloseAnswerBeforeEvent =
         ev.event === "file_edit"
-        || ev.event === "session_message"
         || (
           ev.event === "message"
           && (ev.kind === "tool_hint" || ev.kind === "progress")
         );
       flushPendingStreamEvents({ closeAnswerSegment: shouldCloseAnswerBeforeEvent });
 
-      if (ev.event === "session_message") {
-        clearActivitySegment();
-        setIsStreaming(true);
-        setMessages((prev) => appendLiveSessionMessage(prev, ev));
-        return;
-      }
-
       if (ev.event === "reasoning_end") {
         if (suppressStreamUntilTurnEndRef.current) return;
         setMessages((prev) => closeReasoningStream(prev, Date.now()));
@@ -1188,9 +1171,6 @@ export function useNanobotStream(
             ...(options?.sessionMentions?.length
               ? { sessionMentions: options.sessionMentions }
               : {}),
-            ...(options?.sessionHandles?.length
-              ? { sessionHandles: options.sessionHandles }
-              : {}),
           },
         ];
       });