feat: support install browser in chat

channel/web/static/js/console.js

@@ -891,6 +891,15 @@ function startSSE(requestId, loadingEl, timestamp) {
             mediaEl.appendChild(fileEl);
             scrollChatToBottom();
 
+        } else if (item.type === 'phase') {
+            // Coarse progress (e.g. cow install-browser); must not close SSE (unlike "done")
+            ensureBotEl();
+            const wrap = document.createElement('div');
+            wrap.className = 'text-xs sm:text-sm text-slate-600 dark:text-slate-400 border-l-2 border-primary-400 pl-2 py-1 my-0.5';
+            wrap.textContent = String(item.content || '');
+            stepsEl.appendChild(wrap);
+            scrollChatToBottom();
+
         } else if (item.type === 'done') {
             es.close();
             delete activeStreams[requestId];

channel/web/web_channel.py

@@ -96,10 +96,22 @@ class WebChannel(ChatChannel):
                 logger.error(f"No session_id found for request {request_id}")
                 return
 
-            # SSE mode: push done event to SSE queue
+            # SSE mode: push events to SSE queue
             if request_id in self.sse_queues:
                 content = reply.content if reply.content is not None else ""
 
+                # Intermediate status lines (e.g. /install-browser phases) must NOT use "done",
+                # or the frontend closes EventSource and drops subsequent events.
+                if getattr(reply, "sse_phase", False):
+                    self.sse_queues[request_id].put({
+                        "type": "phase",
+                        "content": content,
+                        "request_id": request_id,
+                        "timestamp": time.time(),
+                    })
+                    logger.debug(f"SSE phase for request {request_id}")
+                    return
+
                 # Files are already pushed via on_event (file_to_send) during agent execution.
                 # Skip duplicate file pushes here; just let the done event through.
                 if reply.type in (ReplyType.IMAGE_URL, ReplyType.FILE) and content.startswith("file://"):