Read and write files through Zed (#6169)

Co-authored-by: Agus Zubiaga <agus@zed.dev>

packages/core/src/tools/write-file.ts

@@ -80,7 +80,9 @@ export async function getCorrectedFileContent(
   let correctedContent = proposedContent;
 
   try {
-    originalContent = fs.readFileSync(filePath, 'utf8');
+    originalContent = await config
+      .getFileSystemService()
+      .readTextFile(filePath);
     fileExists = true; // File exists and was read
   } catch (err) {
     if (isNodeError(err) && err.code === 'ENOENT') {
@@ -261,7 +263,9 @@ class WriteFileToolInvocation extends BaseToolInvocation<
         fs.mkdirSync(dirName, { recursive: true });
       }
 
-      fs.writeFileSync(file_path, fileContent, 'utf8');
+      await this.config
+        .getFileSystemService()
+        .writeTextFile(file_path, fileContent);
 
       // Generate diff for display result
       const fileName = path.basename(file_path);