chore: update STT model copy and tidy UI styles

[ComputelessComputer]

• Refactored UI components with styling improvements
• Updated speech-to-text model description
• Simplified placeholder component for note input
• Modified default Tiptap document structure
• Reordered Tailwind CSS classes for better consistency

---

This is part 2 of 2 in a stack made with GitButler:

•  2  chore: update STT model copy and tidy UI styles #1930 👈
•  1  Refactor UI component styling with updated rounded designs #1899

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch c-branch-7

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}