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/AnchorNav.css

@@ -5,11 +5,11 @@
 
 .aa-anchor-item {
   display: block; padding: 6px 12px; font-size: 13px; color: var(--au-color-text-secondary); cursor: pointer;
-  border-left: 2px solid var(--au-color-border); line-height: 1.4; transition: color .15s, border-color .15s; background: none; border-top: none; border-right: none; border-bottom: none; text-align: left; width: 100%;
+  border-inline-start: 2px solid var(--au-color-border); line-height: 1.4; transition: color .15s, border-color .15s; background: none; border-top: none; border-inline-end: none; border-bottom: none; text-align: start; width: 100%;
 }
 .aa-anchor-item:hover { color: var(--au-color-brand); }
 .aa-anchor-item.is-active { color: var(--au-color-brand); border-left-color: var(--au-color-brand); font-weight: 500; }
 
-.aa-anchor-sub { padding-left: 8px; }
-.aa-anchor-sub .aa-anchor-item { border-left: none; padding-left: 20px; }
-.aa-anchor-sub .aa-anchor-item.is-active { border-left: 2px solid var(--au-color-brand); }
+.aa-anchor-sub { padding-inline-start: 8px; }
+.aa-anchor-sub .aa-anchor-item { border-inline-start: none; padding-inline-start: 20px; }
+.aa-anchor-sub .aa-anchor-item.is-active { border-inline-start: 2px solid var(--au-color-brand); }