Remove HTML Preview Tool from navigation and add to gitignore

- Removed HTML Preview Tool from navigation menu in Layout.js
- Cleaned up unused Code import
- Added HTML Preview related files to .gitignore
- Project builds successfully without HTML Preview Tool

src/pages/HtmlPreviewTool.js

@@ -316,7 +316,7 @@ const HtmlPreviewTool = () => {
               <div className="p-4 border-b border-gray-200 dark:border-gray-700">
                 <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100">Code Editor</h2>
               </div>
-              <div className="flex-1 p-4 overflow-y-auto">
+              <div className="flex-1 flex flex-col p-4">
                 <CodeInputs
                   htmlInput={htmlInput}
                   setHtmlInput={setHtmlInput}
@@ -381,7 +381,7 @@ const HtmlPreviewTool = () => {
     <ToolLayout title="HTML Preview Tool">
       <div className={`flex h-full ${inspectedElementInfo ? 'gap-4' : 'gap-6'}`}>
         {/* Left column - Code inputs */}
-        <div className={`space-y-6 transition-all duration-300 ${
+        <div className={`flex flex-col transition-all duration-300 ${
           inspectedElementInfo ? 'flex-1' : 'w-1/2'
         }`}>
           <CodeInputs