feat: pass source path to markdown parser for icon resolution

Pass the file's base path through the markdown parsing pipeline to
allow the icon directive to resolve relative asset paths correctly
using an absolute fallback chain.

src/markdown/index.ts

@@ -6,7 +6,7 @@ import markedTable from "./table";
 import { gfmHeadingId } from "marked-gfm-heading-id";
 import markedColumns from "./columns";
 import markedCodeBlockYamlTag from "./code-block-yaml-tag";
-import { iconDirective } from "./icon";
+import { iconDirective, setIconBase } from "./icon";
 
 // 使用 marked-directive 来支持指令语法
 const marked = new Marked()
@@ -33,7 +33,8 @@ const marked = new Marked()
     },
   );
 
-export function parseMarkdown(content: string): string {
+export function parseMarkdown(content: string, basePath?: string): string {
+  setIconBase(basePath);
   return marked.parse(content.trimStart()) as string;
 }