feat: implement icon directive with relative path fallback

Refactor icon rendering to use a custom `marked-directive` instead of
a global icon prefix. This allows icons to use a CSS-based fallback
chain (searching up to 10 directory levels for an `assets/` folder),
making icon paths more robust and removing the need to pass path
prefixes through the component tree.

src/components/Article.tsx

@@ -7,20 +7,17 @@ import {
   onCleanup,
   Show,
   createResource,
-  createMemo,
   createSignal,
 } from "solid-js";
 import { parseMarkdown } from "../markdown";
 import { extractSection } from "../data-loader";
 import mermaid from "mermaid";
 import { getIndexedData } from "../data-loader/file-index";
-import { resolvePath } from "./utils/path";
 import { useNavigateWithParams } from "./useNavigateWithParams";
 
 export interface ArticleProps {
   src: string;
   section?: string; // 指定要显示的标题（不含 #）
-  iconPath?: string; // 图标路径前缀，默认为 "./assets"，空字符串表示禁用
   onLoaded?: () => void;
   onError?: (error: Error) => void;
   class?: string; // 额外的 class 用于样式控制
@@ -83,12 +80,6 @@ export const Article: Component<ArticleProps & ParentProps> = (props) => {
   );
   const [contentDom, setContentDom] = createSignal<HTMLDivElement>();
 
-  // 解析 iconPath，默认为 "./assets"，空字符串表示禁用
-  const iconPrefix = createMemo(() => {
-    if (props.iconPath === "") return undefined; // 空字符串禁用图标前缀
-    return resolvePath(props.src, props.iconPath ?? "./assets");
-  });
-
   createEffect(() => {
     const data = content();
     if (data) {
@@ -144,7 +135,7 @@ export const Article: Component<ArticleProps & ParentProps> = (props) => {
           <div
             class="relative"
             ref={setContentDom}
-            innerHTML={parseMarkdown(content()!, iconPrefix())}
+            innerHTML={parseMarkdown(content()!)}
           />
           {props.children}
         </ArticleDomCtx.Provider>

src/components/md-deck/CardLayer.tsx

@@ -4,7 +4,6 @@ import { getLayerStyle } from "./hooks/dimensions";
 import type { CardData, CardSide, LayerConfig } from "./types";
 import { DeckStore } from "./hooks/deckStore";
 import { processVariables } from "../utils/csv-loader";
-import { resolvePath } from "../utils/path";
 import type { LayerInteractionHandlers } from "./hooks/useLayerInteraction";
 
 export interface CardLayerProps {
@@ -26,13 +25,8 @@ export function CardLayer(props: CardLayerProps) {
   const draggingState = () => props.store.state.draggingState;
 
   function renderLayerContent(content: string) {
-    const iconPath = resolvePath(
-      props.store.state.cards.sourcePath,
-      props.cardData.iconPath ?? "./assets",
-    );
     return parseMarkdown(
       processVariables(content, props.cardData, props.store.state.cards),
-      iconPath,
     ) as string;
   }
 

src/components/md-embed.tsx

@@ -1,5 +1,5 @@
 import { customElement, noShadowDOM } from "solid-element";
-import { createResource, Show, createMemo, createEffect } from "solid-js";
+import { createResource, Show, createEffect } from "solid-js";
 import { getIndexedData } from "../data-loader/file-index";
 import { extractSection } from "../data-loader";
 import { parseMarkdown } from "../markdown";
@@ -27,9 +27,6 @@ customElement("md-embed", { headingBase: 0 }, (props, { element }) => {
   const articlePath = articleEl?.getAttribute("data-src") || "";
   const resolvedPath = resolvePath(articlePath, filePath);
 
-  // 计算嵌入文件的 iconPrefix，用 createMemo 包装避免每个 embed 都重新计算
-  const iconPrefix = createMemo(() => resolvePath(resolvedPath, "./assets"));
-
   const [content] = createResource(
     () => ({ path: resolvedPath, section }),
     async ({ path, section }) => {
@@ -56,10 +53,7 @@ customElement("md-embed", { headingBase: 0 }, (props, { element }) => {
       </Show>
       <Show when={!content.loading && !content.error && content()}>
         {/* biome-ignore lint/security/noDangerouslySetInnerHtml: markdown render */}
-        <div
-          class="prose"
-          innerHTML={parseMarkdown(content()!, iconPrefix())}
-        />
+        <div class="prose" innerHTML={parseMarkdown(content()!)} />
       </Show>
     </div>
   );