feat(playground): enhance PlaygroundPage with Monaco editor focus and position handling

src/app/playground/page.tsx

@@ -1,6 +1,7 @@
 "use client";
 
-import { useState } from "react";
+import * as monaco from "monaco-editor";
+import { useRef, useState } from "react";
 import { Editor } from "@monaco-editor/react";
 import { Tabs, TabsList, TabsTrigger } from "@/components/ui/tabs";
 import { ScrollArea, ScrollBar } from "@/components/ui/scroll-area";
@@ -39,6 +40,7 @@ int main() {
 };
 
 export default function PlaygroundPage() {
+  const editorRef = useRef<monaco.editor.IStandaloneCodeEditor | null>(null);
   const [language, setLanguage] = useState<keyof typeof files>("c");
   const file = files[language];
 
@@ -98,6 +100,20 @@ export default function PlaygroundPage() {
         defaultLanguage={file.language}
         defaultValue={file.value}
         options={{ automaticLayout: true }}
+        onMount={(editor) => {
+          editorRef.current = editor;
+          const model = editor.getModel();
+          if (model) {
+            const lineCount = model.getLineCount();
+            const lastLineLength = model.getLineLength(lineCount);
+            editor.setPosition({
+              lineNumber: lineCount,
+              column: lastLineLength + 1,
+            });
+            editor.focus();
+            console.log(editor.getModel()?.uri.path);
+          }
+        }}
       />
     </div>
   );