feat: stop/cancel intent detection

wwwroot/api/cockpit_chat_v2.dspy

@@ -34,6 +34,14 @@ def _w_card(title, body, kind="info"):
 
 if action == 'send_message':
     prompt = msg
+
+    # ── 意图识别：停止类指令 ──
+    stop_keywords = ['停止', '取消', '停下', '终止', '停', 'stop', 'cancel', 'abort']
+    if any(kw == prompt.strip().lower() or kw in prompt.strip().lower() for kw in stop_keywords):
+        async def _stop_stream():
+            yield json.dumps(_w_md("已停止当前任务。"), ensure_ascii=False) + '\n'
+        return await stream_response(request, _stop_stream, 'text/plain; charset=utf-8')
+
     uid = await get_user()
     if not uid:
         uid = 'user-01'  # 测试兼容