fix: remove require.resolve warnings in preset-ifla plugins

- Change plugin references from require.resolve() to direct strings
- Resolves webpack warning about external dependencies
- Affects docusaurus-plugin-sass, @docusaurus/plugin-ideal-image, and @easyops-cn/docusaurus-search-local

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: jonphipps

packages/preset-ifla/src/index.ts

@@ -27,11 +27,11 @@ export default function preset(
 
     plugins: [
       // Sass support
-      require.resolve('docusaurus-plugin-sass'),
+      'docusaurus-plugin-sass',
 
       // Ideal image optimization
       [
-        require.resolve('@docusaurus/plugin-ideal-image'),
+        '@docusaurus/plugin-ideal-image',
         {
           quality: 70,
           max: 1030,
@@ -43,7 +43,7 @@ export default function preset(
 
       // Local search functionality
       [
-        require.resolve('@easyops-cn/docusaurus-search-local'),
+        '@easyops-cn/docusaurus-search-local',
         {
           hashed: true,
           indexBlog: false,