…rget': parameter 1 is not of type 'Event' (#30612)

## **Description**

Fix `TypeError: Failed to execute 'dispatchEvent' on 'EventTarget':
parameter 1 is not of type 'Event'` crash caused by the `CloseEvent`
polyfill in `shim.js` using `event-target-shim`'s `Event` class instead
of React Native's own `Event` class. When `@nktkas/rews` (Hyperliquid
SDK WebSocket transport) dispatches a `CloseEvent` on the native
WebSocket, RN's `dispatchEvent` validates `event instanceof RNEvent` —
which failed because `event-target-shim` provides a different `Event`
class.

Replaced `event-target-shim` globals with React Native's own `Event`,
`EventTarget`, `CloseEvent`, and `MessageEvent` classes so all
`instanceof` checks pass consistently.

## **Changelog**

CHANGELOG entry: Fixed a crash caused by CloseEvent dispatch on
WebSocket failing instanceof validation

## **Related issues**

Fixes:
[TAT-3223](https://consensyssoftware.atlassian.net/browse/TAT-3223)

## **Manual testing steps**

```gherkin
Feature: CloseEvent dispatch on native WebSocket

  Scenario: CloseEvent is dispatched on native WebSocket without error
    Given the app is running with Hyperliquid SDK active

    When a WebSocket connection is closed while in CONNECTING state
    Then no TypeError is thrown
    And the CloseEvent is dispatched successfully
```

## **Screenshots/Recordings**

State-only fix: no visual evidence needed. Both ACs proven via CDP eval
(CloseEvent dispatch success) and lint:tsc (no TS errors).

## **Pre-merge author checklist**

- [x] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I've included tests if applicable
- [x] I've documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I've applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

## **Validation Recipe**

<details>
<summary>recipe.json</summary>

```json
{
  "pr": "TAT-3223",
  "title": "CloseEvent dispatchEvent on native WebSocket must not throw TypeError",
  "jira": "TAT-3223",
  "acceptance_criteria": [
    "CloseEvent dispatched on native WebSocket must not throw TypeError",
    "No new TypeScript errors introduced by the fix"
  ],
  "validate": {
    "static": ["yarn lint:tsc"],
    "workflow": {
      "pre_conditions": ["wallet.unlocked"],
      "entry": "ac1-eval-closeevent-dispatch",
      "nodes": {
        "ac1-eval-closeevent-dispatch": {
          "action": "eval_sync",
          "expression": "(function() { try { var ws = new WebSocket('wss://echo.websocket.org'); var ce = new CloseEvent('close', {code: 1006, reason: '', wasClean: false}); ws.dispatchEvent(ce); ws.close(); return JSON.stringify({success: true, error: null}); } catch(e) { return JSON.stringify({success: false, error: e.message}); } })()",
          "assert": { "operator": "eq", "field": "success", "value": true },
          "next": "ac1-eval-closeevent-props"
        },
        "ac1-eval-closeevent-props": {
          "action": "eval_sync",
          "expression": "(function() { var ce = new CloseEvent('close', {code: 1006, reason: 'test', wasClean: true}); return JSON.stringify({type: ce.type, code: ce.code, reason: ce.reason, wasClean: ce.wasClean}); })()",
          "assert": {
            "all": [
              { "operator": "eq", "field": "code", "value": 1006 },
              { "operator": "eq", "field": "reason", "value": "test" },
              { "operator": "eq", "field": "wasClean", "value": true }
            ]
          },
          "next": "ac1-eval-messageevent-dispatch"
        },
        "ac1-eval-messageevent-dispatch": {
          "action": "eval_sync",
          "expression": "(function() { try { var ws = new WebSocket('wss://echo.websocket.org'); var me = new MessageEvent('message', {data: 'hello'}); ws.dispatchEvent(me); ws.close(); return JSON.stringify({success: true, error: null}); } catch(e) { return JSON.stringify({success: false, error: e.message}); } })()",
          "assert": { "operator": "eq", "field": "success", "value": true },
          "next": "setup-done"
        },
        "setup-done": {
          "action": "end",
          "status": "pass"
        }
      }
    }
  }
}
```

</details>

## **Recipe Workflow**

<details>
<summary>workflow.mmd</summary>

```mermaid
graph TD
    ac1-eval-closeevent-dispatch["ac1-eval-closeevent-dispatch<br/>eval_sync: CloseEvent dispatch on native WS"]
    ac1-eval-closeevent-props["ac1-eval-closeevent-props<br/>eval_sync: Verify CloseEvent properties"]
    ac1-eval-messageevent-dispatch["ac1-eval-messageevent-dispatch<br/>eval_sync: MessageEvent dispatch on native WS"]
    setup-done["setup-done<br/>end: pass"]

    ac1-eval-closeevent-dispatch --> ac1-eval-closeevent-props
    ac1-eval-closeevent-props --> ac1-eval-messageevent-dispatch
    ac1-eval-messageevent-dispatch --> setup-done
```

</details>


[TAT-3223]:
https://consensyssoftware.atlassian.net/browse/TAT-3223?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Touches app bootstrap polyfills used by Hyperliquid WebSockets; low
blast radius but wrong globals could break perps connectivity at
runtime.
> 
> **Overview**
> Fixes a **Hyperliquid / perps WebSocket crash** where `dispatchEvent`
rejected `CloseEvent` because polyfilled events did not pass React
Native’s `instanceof Event` check.
> 
> **`shim.js`** stops using **`event-target-shim`** and hand-rolled
`CloseEvent` / `MessageEvent` constructors. When globals are missing, it
assigns React Native’s own **`Event`**, **`EventTarget`**,
**`CloseEvent`**, and **`MessageEvent`** from RN private web API modules
so events dispatched by `@nktkas/rews` match what RN’s WebSocket
`EventTarget` expects.
> 
> **`event-target-shim`** is removed from **`package.json`** / lockfile.
**`shim.test.js`** adds unit coverage for RN `CloseEvent` and
`MessageEvent` properties and inheritance.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
5d5cb89. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->