fix(FileTree): use base path for anchor navigation

src/components/Article.tsx

@@ -108,7 +108,10 @@ export const Article: Component<ArticleProps & ParentProps> = (props) => {
       if (href.startsWith("#")) return;
 
       e.preventDefault();
-      navigate(href);
+      // Resolve relative hrefs against the current page path so that
+      // e.g. "blah.md" on /content/page.md becomes /content/blah.md
+      const resolved = new URL(href, window.location.origin + window.location.pathname).pathname;
+      navigate(resolved);
     };
 
     dom.addEventListener("click", onClick);

src/components/FileTree.tsx

@@ -115,7 +115,7 @@ export const HeadingNode: Component<{
     if (e.button === 0) {
       // Left-click: use SPA navigation
       e.preventDefault();
-      navigate(href());
+      navigate(`${props.basePath}#${anchor}`);
     }
     // Middle-click / right-click: let the browser handle the <a> natively
     // 滚动到目标元素，考虑导航栏高度偏移