feat: add always inline editor option for multiline messages

[lunar-seal]

Description

Fixes #1181
Add an option to force the text editor to stay inline with the buttons. See the corresponding issue.
Keep current editor style as default, as it's unique.
This changes the alignment of the items in the text editor row to "end" for the classic editor too. This does not change behavior.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).

I used Opus 4.8 for generating the settings boilerplate. I manually reviewed and edited all generated output.