feat(chat): step counter on running task, surface sibling tasks

Stop suppressing tool-call events whose id differs from the active task
when the call itself is another task — sibling parallel-audit subagents
were being dropped on the floor, leaving the matching TOOL_CALL_RESULT
with nothing to bind to until a page reload rehydrated from checkpoint.
For genuinely inner tool calls, tick an innerToolsCount on the parent
task segment so the user has some live signal during the long quiet
window, surfaced as a small "N steps" chip on the running task card.

Author: srtab

daiv/chat/static/chat/js/chat-stream.js

@@ -571,8 +571,17 @@
           seg.endedAt = Date.now();
         }
       } else if (type === AGUI.TOOL_CALL_START) {
-        // If a parent task is running and this isn't the task's own id, suppress.
-        if (activeTask && evt.toolCallId !== activeTask.id) return;
+        // Inner subagent tool calls collapse onto the running task card —
+        // tick a progress counter so the user has *some* signal during the
+        // long quiet window. Sibling task tool calls (parallel audit
+        // subagents, etc.) MUST surface: suppressing them here drops the
+        // segment, and the matching TOOL_CALL_RESULT then has nothing to
+        // bind to, so the sibling task is invisible until a page reload
+        // rehydrates from the checkpoint.
+        if (activeTask && evt.toolCallId !== activeTask.id && evt.toolCallName !== "task") {
+          activeTask.innerToolsCount = (activeTask.innerToolsCount || 0) + 1;
+          return;
+        }
         // ag_ui_langgraph re-emits START/ARGS/END from OnToolEnd whenever its
         // `has_function_streaming` flag got reset to False by an inner tool
         // completion — which happens for every parent tool that wraps a
@@ -597,14 +606,16 @@
             status: "running",
           });
         } else {
-          turn.segments.push({
+          const seg = {
             type: "tool_call",
             id: evt.toolCallId,
             name: evt.toolCallName,
             args: "",
             result: null,
             status: "running",
-          });
+          };
+          if (evt.toolCallName === "task") seg.innerToolsCount = 0;
+          turn.segments.push(seg);
         }
         this._toolIndex.set(evt.toolCallId, turn.segments.length - 1);
       } else if (type === AGUI.TOOL_CALL_ARGS) {

daiv/chat/templates/chat/chat_detail.html

@@ -134,6 +134,9 @@ <h1 class="chat-hero__title">{% trans "What are we building today?" %}</h1>
                         </span>
                         <span class="chat-tool__name" x-text="toolSignature(seg).label"></span>
                         <span class="chat-tool__path" x-text="toolSignature(seg).path"></span>
+                        <template x-if="seg.name === 'task' && seg.status === 'running' && seg.innerToolsCount">
+                          <span class="chat-tool__progress" x-text="`${seg.innerToolsCount} step${seg.innerToolsCount === 1 ? '' : 's'}`"></span>
+                        </template>
                         <template x-for="b in toolSignature(seg).badges" :key="b.text">
                           <span class="chat-tool__badge" :class="`chat-tool__badge--${b.tone}`" x-text="b.text"></span>
                         </template>

daiv/static_src/css/input.css

@@ -1096,6 +1096,13 @@ a, button, [role="button"] {
   .chat-tool__badge--violet  { background: rgba(167, 139, 250, 0.12); color: #c4b5fd; }
   .chat-tool__badge--neutral { background: rgba(255, 255, 255, 0.04); color: #94a3b8; }
 
+  .chat-tool__progress {
+    font-size: 10.5px;
+    color: rgba(251, 191, 36, 0.8);
+    font-variant-numeric: tabular-nums;
+    flex-shrink: 0;
+  }
+
   .chat-tool__chev {
     color: #475569;
     transition: transform 0.2s ease;