[Question]: Is the Eth Sign modal input supposed to be case sensitive?

### Describe the bug

If you type in
`I only sign what i understand` or `i only sign what i understand`
instead of
`I only sign what I understand`
you cannot proceed.

I find it inconvinient that the lowercase `I` is not allowed.

Is this intended to increase friction?

### Steps to reproduce

1. log in
2. settings
3. advanced
4. enable eth sign

### Error messages or log output

_No response_

### Version

10.32

### Build type

None

### Browser

Chrome

### Operating system

MacOS

### Hardware wallet

_No response_

### Additional context

_No response_

Start by reproducing the behavior through Settings > Advanced with the Eth Sign modal, using the two lowercase variants described in the issue. Trace the modal's confirmation entry point and its existing tests, then determine whether case-insensitive input is intended; done means the behavior is confirmed and covered by an appropriate test or the intended restriction is documented.

Written by the indexing model from the issue text.