[CHORE] Update example-app to use Capacitor 8 compatible plugin version (v8.0.0)

**Is your feature request related to a problem? Please describe.**
The repo has been updated to support **Capacitor 8** (plugin **v8.0.0**), but the **example-app** still appears to be **Capacitor 7 compatible** / pinned to older Capacitor dependencies. This makes the example-app outdated and potentially confusing for users who want to validate the latest plugin version in a Capacitor 8 project.

**Describe the solution you'd like**
Update the **example-app** to use the latest Capacitor 8 compatible setup and the latest plugin version, and confirm it builds/runs successfully.

Suggested scope:
- Upgrade example-app dependencies to **Capacitor 8** (`@capacitor/core`, `@capacitor/cli`, platform packages, etc.).
- Update the example-app to use the latest plugin version (**v8.0.0**) from this repo.
- Run through iOS/Android build verification (and apply any required config changes):
- iOS: ensure correct deployment target / Pod install (if applicable), build in Xcode.
- Android: verify Gradle + build tools compatibility and that the plugin integrates cleanly.