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

[ryaa]

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 This makes the example-app outdated and potentially confusing for users who want to validate the latest plugin version in a Capacitor 8 project.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.