Keep the handoff continuation message when its turn is folded away

web/src/task.ts

@@ -67,6 +67,7 @@ type Ctx = {
   taskId: string | undefined;
   lastMessage: HTMLElement | undefined;
   turnStart: HTMLElement | undefined;
+  keepTurnStart: boolean;
   quiet: boolean;
   handoff: { summary: HTMLElement; body: HTMLElement } | undefined;
   watchReport: (el: HTMLElement, itemId: string) => void;
@@ -237,6 +238,7 @@ export function mountChat(root: HTMLElement, src: ChatSource, makeHead: (rerende
     unplaced: [],
     lastMessage: undefined,
     turnStart: undefined,
+    keepTurnStart: false,
     quiet: false,
     handoff: undefined,
     root: src.root(),
@@ -529,7 +531,7 @@ export function mountChat(root: HTMLElement, src: ChatSource, makeHead: (rerende
         openHandoff();
       }
       if (ev.kind === "turn.ended" && ctx.quiet && ctx.turnStart?.parentNode === transcript) {
-        let node: ChildNode | null = ctx.turnStart;
+        let node: ChildNode | null = ctx.keepTurnStart ? ctx.turnStart.nextSibling : ctx.turnStart;
         while (node && node !== spinner) {
           const next: ChildNode | null = node.nextSibling;
           node.remove();
@@ -542,6 +544,7 @@ export function mountChat(root: HTMLElement, src: ChatSource, makeHead: (rerende
       put(el);
       if (ev.kind === "user.message" && p["mid_turn"] !== true) {
         ctx.turnStart = el;
+        ctx.keepTurnStart = p["continuation"] === true;
       }
       if (ev.kind === "turn.ended" || ev.kind === "inbox.created") {
         addAnchor(ev.seq, el, ev.kind === "turn.ended");