Add power on button to disabled banner

[davertay-j]

Adds a liveBluetoothPowerRequest that tickles the BLE system to throw up the system alert. This is wired into a new button on the error banner.

Demo

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Note

Low Risk
Small UI wiring plus a one-off CoreBluetooth manager for the system power alert; no changes to the main BLE coordinator or auth/data paths.

Overview
When Bluetooth is powered off, the error banner now shows a power button (alongside the existing Enable flow for unauthorized state).

Tapping it runs an injectable requestPowerOn hook on BluetoothSystemState, wired from TopazMain to liveBluetoothPowerRequest, which creates a short-lived CBCentralManager with CBCentralManagerOptionShowPowerAlertKey so iOS can surface the system “turn on Bluetooth” alert. WebContainerModel forwards the tap from BluetoothErrorView into that shared hook.

^{Reviewed by Cursor Bugbot for commit c88ce5e. Configure here.}