get_core_info

The address of the phone's index and the credentials that open it. The app talks to its index directly with them.

When the app calls it:

• right after the index is created, a few times until it answers;
• when the index refuses the password the phone holds: Opensolr can give the index new credentials, and the app reads them here and repeats the request once;
• at the start of a sync, only when photos_sync_info could not answer.

The app reads connection_url, auth_username, auth_password and environment_identifier. It refuses an address that is not HTTPS: The index does not offer an HTTPS address. The password is kept on the phone encrypted.

NOT_OWNER_ERROR means the index is not in the account; the app treats it as missing, and creates it only after the index list confirms it.