资源卡文档分区：Markdown/纯文本显示前几行，代码文件改画代码图标

- index.tsx：卡面据 projectResourceCardPreviewVariant 分流，代码卡分支只渲染 lucide 代码图标 + 扩展名标签，不再显示文件内容
- index.tsx：文档卡改用 projectResourceDocumentPreviewText 取前 3 行，并带上 data-document-preview-variant 便于排障与验收
- index.tsx：引入 FileCode2 图标
- ResourcePreviewMedia.tsx：弹窗宿主里代码文件同样改画代码图标，避免看起来像"读不出来的图片"
- styles.css：文档卡预览保留换行并限制 3 行（white-space: pre-line + -webkit-line-clamp: 3）
- styles.css：新增 .game-resource-card-code-visual / .game-resource-card-code-label，复用现有卡片色板与居中排布口径

apps/ai-game-creator-shell/src/styles.css

@@ -7209,9 +7209,38 @@ iframe.preview-frame {
   font-size: 11px;
   line-height: 1.55;
   text-align: left;
-  white-space: normal;
+  /* 文档卡预览改为"前几行"（最多 3 行），必须保留换行：折成一行就看不出结构了。 */
+  white-space: pre-line;
+  word-break: break-word;
   -webkit-box-orient: vertical;
-  -webkit-line-clamp: 5;
+  -webkit-line-clamp: 3;
+}
+
+/*
+ * 代码文件卡：不显示文件内容，只给代码图标 + 扩展名标签。
+ * 与 `.game-resource-card-version-visual` 共用同一套居中排布口径，视觉上仍是同一族卡片。
+ */
+.game-resource-card-code-visual {
+  display: grid;
+  gap: 8px;
+  width: 100%;
+  height: 100%;
+  background: linear-gradient(145deg, #fff8f1, #f2ded2);
+  color: #8b5b45;
+  /* 图标与标签作为一组整体垂直居中，与 `.game-resource-card-version-visual` 同口径。 */
+  align-content: center;
+  place-items: center;
+}
+
+.game-resource-card-code-label {
+  padding: 1px 7px;
+  border: 1px solid rgb(139 91 69 / 28%);
+  border-radius: 999px;
+  background: rgb(255 255 255 / 72%);
+  color: #8b5b45;
+  font-size: 9px;
+  font-weight: 700;
+  letter-spacing: 0.04em;
 }
 
 .game-resource-card-version-visual {

apps/ai-game-creator-shell/src/view/project-development/ResourcePreviewMedia.tsx

@@ -1,9 +1,10 @@
-import { Image as ImageIcon, Music2, Video } from 'lucide-react';
+import { FileCode2, Image as ImageIcon, Music2, Video } from 'lucide-react';
 import { useEffect, useRef } from 'react';
 
 import {
   projectResourceCardPreviewKind,
   type ProjectResourceCardPreviewState,
+  projectResourceCardPreviewVariant,
 } from './resourceCardPreviewModel';
 import type { ProjectResource } from './resourceProjectionModel';
 
@@ -79,6 +80,13 @@ export function ResourcePreviewMedia({
   }, [onObservePreview, previewIdentity, resource]);
 
   const kind = resource ? projectResourceCardPreviewKind(resource) : null;
+  /**
+   * 代码文件走与资源卡一致的分流：不画内容（本组件本来也只画缩略图 / 占位），
+   * 占位图标换成代码图标，免得弹窗里代码文件看起来像"读不出来的图片"。
+   */
+  const previewVariant = resource
+    ? projectResourceCardPreviewVariant(resource)
+    : null;
   const sourceUrl =
     preview.status === 'loaded' ? (preview.preview.sourceUrl ?? null) : null;
   const visual = (() => {
@@ -111,6 +119,9 @@ export function ResourcePreviewMedia({
         />
       );
     }
+    if (previewVariant === 'code') {
+      return <FileCode2 className="h-5 w-5" aria-hidden="true" />;
+    }
     return resourcePreviewPlaceholderIcon(
       kind === 'video'
         ? 'video'

apps/ai-game-creator-shell/src/view/project-development/index.tsx

@@ -18,6 +18,7 @@ import { save as saveNativeFileDialog } from '@tauri-apps/plugin-dialog';
 import {
   AtSign,
   Crosshair,
+  FileCode2,
   FileText,
   FolderTree,
   Gamepad2,
@@ -275,7 +276,9 @@ import {
 import {
   projectResourceCardPreviewKind,
   type ProjectResourceCardPreviewState,
-  summarizeProjectResourceDocument,
+  projectResourceCardPreviewVariant,
+  projectResourceCodeTypeLabel,
+  projectResourceDocumentPreviewText,
 } from './resourceCardPreviewModel';
 import { ResourceClassificationPanel } from './ResourceClassificationPanel';
 import {
@@ -757,9 +760,24 @@ const ResourceCard = memo(function ResourceCard({
   const mediaActive = activeMediaIdentity === previewIdentity;
   const sourceUrl =
     preview.status === 'loaded' ? preview.preview.sourceUrl : null;
-  const documentSummary =
-    preview.status === 'loaded' && preview.preview.content !== undefined
-      ? summarizeProjectResourceDocument(preview.preview.content)
+  /**
+   * 文档类卡片的卡面分流结论（`markdown` / `code` / `plain-text` / `null`）。
+   *
+   * 判据只看路径扩展名与 subtype，**不依赖是否读到内容** —— 代码卡的卡面本就不该有内容，
+   * 等读完再决定画什么只会把"丑预览"和多余 IO 一起留在链路上。
+   */
+  const previewVariant = projectResourceCardPreviewVariant(resource);
+  /** 代码卡的类型标签（`.tsx` → `TSX`）；不是代码卡时为 `null`。 */
+  const codeTypeLabel = projectResourceCodeTypeLabel(resource.path);
+  const documentPreview =
+    preview.status === 'loaded' &&
+    preview.preview.content !== undefined &&
+    previewVariant !== null &&
+    previewVariant !== 'code'
+      ? projectResourceDocumentPreviewText(
+          preview.preview.content,
+          previewVariant === 'markdown',
+        )
       : '';
 
   useEffect(() => {
@@ -908,10 +926,31 @@ const ResourceCard = memo(function ResourceCard({
         </span>
       );
     }
-    if ((kind === 'document' || kind === 'code') && documentSummary) {
+    /**
+     * 代码文件卡：**不显示内容**，只给代码图标 + 类型标签。
+     *
+     * 这里的判据是路径分流（`previewVariant === 'code'`），与是否读到内容无关 ——
+     * 代码卡压根不发起读取（见 `useProjectResourceCardPreviews` 的入队门禁）。
+     */
+    if (previewVariant === 'code') {
       return (
-        <span className="game-resource-card-document-summary">
-          {documentSummary}
+        <span className="game-resource-card-code-visual">
+          <FileCode2 size={30} aria-hidden="true" />
+          {codeTypeLabel ? (
+            <span className="game-resource-card-code-label">
+              {codeTypeLabel}
+            </span>
+          ) : null}
+        </span>
+      );
+    }
+    if (previewVariant !== null && documentPreview) {
+      return (
+        <span
+          className="game-resource-card-document-summary"
+          data-document-preview-variant={previewVariant}
+        >
+          {documentPreview}
         </span>
       );
     }