fix: 修复 Gitignore 生成器 JavaScript 语法错误

将 GITIGNORE_TEMPLATES 对象中的字符串从单引号改为模板字符串(反引号)，以支持多行字符串格式。

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: chao5go

tools/gitignore-generator/app.html

@@ -160,27 +160,27 @@ <h1>Gitignore 生成器</h1>
 
     <script>
         const GITIGNORE_TEMPLATES = {
-                node: 'node_modules/
+            node: `node_modules/
 .DS_Store
 .npm
 .env
-',
-                python: '__pycache__/
+`,
+            python: `__pycache__/
 *.pyc
 .env
 .venv/
-',
-                java: '*.class
+`,
+            java: `*.class
 *.jar
 .target/
-',
-                macos: '.DS_Store
+`,
+            macos: `.DS_Store
 .AppleDouble
-',
-                windows: 'Thumbs.db
+`,
+            windows: `Thumbs.db
 Desktop.ini
-'
-            };
+`
+        };
 
             function generateGitignore() {
                 const selected = Array.from(document.querySelectorAll('.checkbox-group input:checked'))