fix(cli): ExternalObject type decalare

cli/src/build.ts

@@ -344,9 +344,13 @@ async function processIntermediateTypeFile(
     .split('\n')
     .map((line) => line.trim())
     .filter(Boolean)
-  let dts = `export class ExternalObject<T> {
-  private readonly __type: unique symbol;
-  [val: unique symbol]: T
+  let dts = `/* eslint-disable */
+
+export class ExternalObject<T> {
+  readonly '': {
+    readonly '': unique symbol
+    [K: symbol]: T
+  }
 }\n`
   const classes = new Map<string, string>()
   const impls = new Map<string, string>()

examples/napi/__test__/typegen.spec.ts.md

@@ -8,9 +8,13 @@ Generated by [AVA](https://avajs.dev).
 
 > Snapshot 1
 
-    `export class ExternalObject<T> {␊
-      private readonly __type: unique symbol;␊
-      [val: unique symbol]: T␊
+    `/* eslint-disable */␊
+    ␊
+    export class ExternalObject<T> {␊
+      readonly '': {␊
+        readonly '': unique symbol␊
+        [K: symbol]: T␊
+      }␊
     }␊
     export const DEFAULT_COST: number␊
     export function getWords(): Array<string>␊

examples/napi/index.d.ts

@@ -1,6 +1,10 @@
+/* eslint-disable */
+
 export class ExternalObject<T> {
-  private readonly __type: unique symbol;
-  [val: unique symbol]: T
+  readonly '': {
+    readonly '': unique symbol
+    [K: symbol]: T
+  }
 }
 export const DEFAULT_COST: number
 export function getWords(): Array<string>