feat(ios): Respect iOS Auto-Capitalization setting

### Is your feature request related to a problem? Please describe.

When using the Keyman system keyboard on iOS, shift is always enabled until the first character is typed, even with auto-capitalization turned off. So you see shift active when you start a sentence, and also if you double-tap to select a word to replace or retype, whether it was previously capitalized or not and whether it's at the start of a sentence or not.

### Describe the solution you'd like

Always respect iOS Auto-Capitalization setting. If auto-capitalize is turned off, require user interaction to "shift."

### Describe alternatives you've considered

_No response_

### Related issues

There Is a similar issue -- similar in that it was a "respect ios settings" issue -- here: https://github.com/keymanapp/keyman/issues/2549

### Keyman apps

- [ ] Keyman for Android
- [x] Keyman for iPhone and iPad
- [ ] Keyman for Linux
- [ ] Keyman for macOS
- [ ] Keyman for Windows
- [ ] Keyman Developer
- [ ] KeymanWeb
- [ ] Other - give details at bottom of form

### Keyman version

18.0

### Operating system

iOS 26.5.2

### Device

iPhone

### Target application

Any app, using keyman keyboard

### Browser

_No response_

### Keyboard name

sil_euro_latin

### Keyboard version

3.0.4

### Language name

EuroLatin (SIL)

### Additional context

_No response_

Start by reproducing the behavior in Keyman for iPhone and iPad with iOS Auto-Capitalization turned off, including after selecting a word to replace. Trace the iOS keyboard handling involved in shift state and compare behavior with the setting enabled and disabled. Done means shift is not enabled automatically when auto-capitalization is off, while normal capitalization still works when it is on.

Written by the indexing model from the issue text.