[BUG] Push Notifications: APN/FCM config mismatch with documentation

[wildsurfer]

According to the Push Notifications documentation:

If you do not wish to send notifications to one platform, just leave that section blank and any devices that fall into the excluded platform will be excluded from sends.

However, in both v2.3.3 and v3.0.0-beta.9, this behavior does not work as documented. • The "Create Integration" button is only enabled when both APN and FCM configs are fully completed. • This contradicts the documentation, which states that either section can be left blank.

Steps to reproduce: 1. Go to Create Integration → Push Notifications. 2. Fill out only the APN section (leave FCM blank). 3. Observe that the Create Integration button remains disabled.

Expected behavior: The Create Integration button should be enabled when at least one config (APN or FCM) is filled in, matching the documented behavior.

Actual behavior: Both APN and FCM configs must be completed before the integration can be created.