feat(S2-P7+S3-P8): 行为断言6试点全绿+RTL28文件迁移/回归1009-1009

P7: tests/_behaviors.js新建（8动词+@input/@doc定位+同步pump+page-load
    幂等缓存）; _runtime聚合+重载清缓存; _template引入; 6演示页标注;
    79测试页重生成。关键修：runner兜底重跑致行为二轮误报，加缓存解决。
P8: tools/migrate-rtl.mjs新建（白名单dry-run/--write）; 28个CSS转逻辑
    属性；物理清零（排除auto/拼接/居中14处人工例外）；三页RTL零溢出。
回归：100%（79/79页，1009/1009断言，N/A 35）。

frameworks/select.html

@@ -63,7 +63,7 @@
     <h2>1. 单选</h2>
     <div class="row">
       <div class="aa-select" data-select data-mode="single" data-name="city">
-        <div class="aa-select-trigger" role="button" aria-haspopup="listbox" aria-expanded="false" tabindex="0"><span class="placeholder">请选择城市</span><span class="caret">▾</span></div>
+        <div class="aa-select-trigger" role="button" aria-haspopup="listbox" aria-expanded="false" tabindex="0" data-behavior="click-toggles-class:.aa-select|is-open"><span class="placeholder">请选择城市</span><span class="caret">▾</span></div>
         <div class="aa-select-panel" hidden>
           <div class="aa-select-option" role="option" data-value="bj">北京</div>
           <div class="aa-select-option" role="option" data-value="sh">上海</div>