Show Loop APNS environment as info instead of a toggle

[bjorkert]

Loop now uploads isAPNSProduction to the Nightscout profile, same as Trio, and LoopFollow already reads it from there. This removes the manual Production toggle from the Loop APNS settings and shows the current environment under Debug / Info instead, like it is for Trio. The hint in the 400 error message about flipping the toggle is removed too.

Requires a Loop build with LoopKit/NightscoutKit#1 and LoopKit/NightscoutService#25.

[bjorkert]

Why this is safe for people whose Loop doesn't upload isAPNSProduction yet

LoopFollow only writes the APNS environment when the profile contains isAPNSProduction (ProfileManager.swift). If the field is missing, the stored value is kept, and its default is false (development).

• Browser/TestFlight Loop builders: they rebuild every 60–90 days, and LoopWorkspace main already includes NightscoutService#25. Their profile will contain the value after their next rebuild.
• Xcode Loop builders on an older Loop: they need development, which is the default, so remotes keep working.
• Remaining edge case: someone on an older Xcode-built Loop who has Production turned on in LoopFollow (left over from a browser build, an imported settings file, or a mistake). Remotes already fail for them today. With this PR they can't flip the toggle back, but rebuilding Loop fixes it. The current environment is shown under Debug / Info, which makes this case easy to spot.