perf(webview2): avoid queuing fire-and-forget scripts

core/webview2.py

@@ -214,7 +214,7 @@ class Wv2Session:
         self._js_pump = QTimer()
         self._js_pump.setInterval(25)
         self._js_pump.timeout.connect(self._js_pump_tick)
-        self._js_pump.start()
+        # 无回调脚本不进入队列；没有待处理任务时不需要常驻唤醒 UI 线程。
         # 🆕 预热：立即导航 about:blank，让 msedgewebview2 进程/GPU 在 UI 构建期间冷启动
         # （实测本机首次真实页面导航需 12-15s，预热后降到 ~1s）
         try:
@@ -339,8 +339,27 @@ class Wv2Session:
             print("[WV2] navigate error:", ex)
 
     def execute_js(self, script: str):
-        """fire-and-forget（ChatBridge.run_js 的替换，JS 文本完全同构）"""
-        self._js_run(script, None)
+        """执行无需返回值的脚本，不进入结果轮询队列。
+
+        流式正文每个 token 都会走这里。旧实现统一使用
+        ``ExecuteScriptWithResultAsync`` 并把任务放入 ``_js_pending``，高频
+        输出时会在渲染器和 Python 侧同时堆积大量无用结果；WebView2 原生
+        ``ExecuteScriptAsync`` 已经提供了真正的 fire-and-forget 路径。
+        """
+        try:
+            execute_async = getattr(self.core, "ExecuteScriptAsync")
+        except AttributeError:
+            # 兼容旧版/测试替身未暴露 ExecuteScriptAsync 的情况。即使只能
+            # 使用带结果 API，也直接丢弃 Task，不把无用结果放进轮询队列。
+            try:
+                getattr(self.core, "ExecuteScriptWithResultAsync")(script)
+            except BaseException as ex:
+                print("[WV2] execute_js fallback error:", ex)
+            return
+        try:
+            execute_async(script)
+        except BaseException as ex:
+            print("[WV2] execute_js error:", ex)
 
     def execute_js_async(self, script: str, cb):
         """带回调执行：真异步，回调在主线程定时器 tick 中发出（绝不阻塞）"""
@@ -358,13 +377,25 @@ class Wv2Session:
                     pass
             return
         self._js_pending.append([task, cb, time.time()])
+        try:
+            if not self._js_pump.isActive():
+                self._js_pump.start()
+        except Exception:
+            pass
 
     def _js_pump_tick(self):
         if not self._js_pending:
+            try:
+                self._js_pump.stop()
+            except Exception:
+                pass
             return
         import json
-        remaining = []
-        for task, cb, t0 in self._js_pending:
+        # 先摘下本批次；回调中再次入队的任务写入新的 _js_pending，不能被
+        # 本轮收尾赋值覆盖。
+        pending = self._js_pending
+        self._js_pending = []
+        for task, cb, t0 in pending:
             done = False
             try:
                 done = task.IsCompleted
@@ -373,7 +404,7 @@ class Wv2Session:
             if not done and time.time() - t0 > 10:
                 done = True  # 10s 安全超时（渲染器死亡时不永久卡队列）
             if not done:
-                remaining.append([task, cb, t0])
+                self._js_pending.append([task, cb, t0])
                 continue
             result = None
             try:
@@ -395,7 +426,11 @@ class Wv2Session:
                     cb(result)
                 except Exception as ex:
                     print("[WV2] js callback error:", ex)
-        self._js_pending = remaining
+        if not self._js_pending:
+            try:
+                self._js_pump.stop()
+            except Exception:
+                pass
 
     def close(self):
         try: