feat: using ion-tab-bar without ion-tabs or ion-router-outlet

### Prerequisites

- [x] I have read the [Contributing Guidelines](https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#creating-an-issue).
- [x] I agree to follow the [Code of Conduct](https://ionicframework.com/code-of-conduct).
- [x] I have searched for [existing issues](https://github.com/ionic-team/ionic-framework/issues) that already report this problem, without success.

### Ionic Framework Version

v8.x

### Current Behavior

```
[Vue warn]: injection "tabBarData" not found.
Vue warn]: Unhandled error during execution of native event handler
at
at
at
at
at
at

```
### Expected Behavior

to work without the need of ion-tabs or router outlet. The navigation will be done by method.

### Steps to Reproduce

https://stackblitz.com/edit/hknvlmdm

### Code Reproduction URL

https://stackblitz.com/edit/hknvlmdm

### Ionic Info

ionic info

Ionic:

Ionic CLI : 6.18.1 (/usr/local/lib/node_modules/@ionic/cli)
Ionic Framework : @ionic/vue 8.5.3

Capacitor:

Capacitor CLI : 7.2.0
@capacitor/android : 7.2.0
@capacitor/core : 7.2.0
@capacitor/ios : 7.2.0

Utility:

cordova-res : 0.15.4
native-run : 2.0.1

System:

NodeJS : v22.12.0 (/Users/z0lo/.nvm/versions/node/v22.12.0/bin/node)
npm : 10.9.0
OS : macOS

### Additional Information

_No response_

Start with the linked StackBlitz reproduction and inspect the IonTabBar and IonTabButton components involved in the warning. Determine how tab-bar state is provided when ion-tabs and ion-router-outlet are absent, then verify that a standalone tab bar can be used with method-driven navigation without the injection error.

由索引模型根据 Issue 内容生成。