[🐛 Bug]: custom element commands doesn't work with browser runner

Beschreibung

{
  browserName: 'chrome'
}

### What happened?

Custom commands added to the element don't work with the `browser` runner, but correctly works with `local` runner.

### What is your expected behavior?

I expect that my element custom command should works correctly in `browser` runner.

### How to reproduce the bug.

```js
// wdio.conf.js
export const config = {
    runner: "browser",
    specs: [
        './src/**/*.test.js'
    ],
    capabilities: [{
        browserName: 'chrome',
    }],
    mochaOpts: {
        ui: 'bdd',
    },
    before: function (capabilities, specs, browser) {
        browser.addCommand("elemCmd", () => {
            console.log('inside my element command');
        }, true);
    },
}

// src/bro.test.js
it('test', async () => {
    await $("body").elemCmd();
})

./node_modules/.bin/wdio run ./wdio.conf.js

[0-0] Error in "test"
Error: Can't call "elemCmd" on element with selector "body", it is not a function

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct

### Is there an existing issue for this?

- [X] I have searched the existing issues

Contributor Guide

Tech Stack

javascriptnodejs

Domain

testing

Issue Type

bug

SchwierigkeitGeschätzte Implementierungsschwierigkeit für neue Contributors, von 1 für sehr kleine Änderungen bis 5 für Expertenarbeit.

3

Geschätzte ZeitEin grober Zeitrahmen, um zu recherchieren, zu implementieren, zu testen und einen Pull Request vorzubereiten.

half day

AktivitätsstatusWie verfügbar das Issue gerade wirkt: frisch, aktiv, stale, blockiert oder wartet auf Maintainer-Input.

fresh

KlarheitWie klar das Issue die erwartete Änderung, Akzeptanzkriterien und den nächsten Schritt erklärt.

clear

Voraussetzungen

Familiarity with WebdriverIO custom commandsUnderstanding of runner modes

EinsteigerfreundlichkeitEin Score von 1 bis 100, der schätzt, wie zugänglich dieses Issue für First-Time Contributors ist.

40

Research-Richtung

Investigate the difference in custom command registration between the 'browser' and 'local' runners. The issue suggests that element commands added via `browser.addCommand` with the `element` parameter set to `true` work in local mode but fail in browser mode. Focus on the code that handles `addCommand` in the runner's context, specifically for element commands. The bug may be in how the element command wrapper is created or how it resolves the element scope. Look at files like `packages/webdriverio/src/commands/browser/addCommand.ts` and the runner specific implementations in `packages/webdriver runner`.