Add error message when no device authentication has been set up

[codebymini]

Improves device authentication error handling for remote bolus and meal actions by surfacing a clear, actionable message when authentication is unavailable (for example, no passcode/biometric setup).

[codebymini]

Ran test on a new device where biometrics (TouchID) had not been setup. Remove the passcode and tried to send a bolus to Loop. Got error message that I need to setup (atleast) passcode to use remote bolus

[marionbarker]

Approved by test.

[marionbarker]

Test

Built Loop main (4.6.0)

removed passcode from device

• tested that I could send remote carb, it appeared in loop and real-time response returned
• tested that when I attempt to send a bolus, nothing happens

build using the code in this PR

• tested that I could send remote carb, it appeared in loop but no real-time response so I think this branch is missing that feature
• tested that when I attempt to send a bolus, clear error message received