feat: send agent prompt -> prompt agent

frontend/src/views/Agent.vue

@@ -157,14 +157,35 @@
     }
 
     promptHistory.value.push(historyEntry);
-    let res = await backend.sendAction("send-agent-prompt", payload);
 
-    if (res.error) {
-      historyEntry.error = res.error;
-    } else {
-      historyEntry.output = res.response;
+    // prompt-agent is a multiple-result action (like read-stream): one packet
+    // per generated inference.Message, followed by a terminal eof packet. The
+    // callback runs once per packet. Assistant/reasoning content is an open
+    // stream ({streamId}); we read it live via read-stream.
+    historyEntry.output = "";
+    try {
+      await backend.sendAction("prompt-agent", payload, (packet, deferred) => {
+        if (packet.eof) {
+          deferred.resolve(packet);
+        } else {
+          const msg = packet.data;
+          if (msg.role !== 'assistant') return;
+          const content = msg.content;
+          if (content && content.streamId != null) {
+            const stream = backend.readStream(content.streamId);
+            stream.on('data', () => {
+              historyEntry.output = stream.partialContent;
+            });
+          } else if (typeof content === 'string') {
+            historyEntry.output += content;
+          }
+        }
+      });
+    } catch (e) {
+      historyEntry.error = e.message || String(e);
+    } finally {
+      historyEntry.loading = false;
     }
-    historyEntry.loading = false;
   }
 
   function promptKeyDown (event, stage) {