Class PushPropertyPage

The two secrets - the VAPID private key and the Firebase service account - are not fields of the page (CC-PUSH-PWA-PAGES, ruling PP-4): they live in this machine's secrets store under the application's context, never in .iiziPush. Below the property editor a "Secrets" group shows, per secret, whether the store holds it - never its value - and offers Generate (a new VAPID pair: the public key into the container, the private key into the store when the page is saved), Import (a downloaded Firebase service-account JSON, checked, into the store when saved; the Project ID filled from it when empty) and Remove (the secret out of the store at once, confirmed). One Undo reverts the container change; the store is not undone, which the page says.