Font Size in Editor

[eduardoadmdev]

Summary

Adds a font size selection tool to the editor toolbar, behaving similarly to other rich text editors (e.g., MS Word).

Changes

• Added FontSizeButton component.
• UX Improvements:
  • Visual display shows unitless numbers (e.g., "14") while applying specific pixel logic (14px) internally.
  • Auto-detection: The input automatically updates to show the font size of the currently selected text or cursor position.
  • The box acts as a clean input field.
• Added editing-font-size localization string.
• Added strict TypeScript typing for the new component.

Testing

• Manual Test: Verified that selecting text updates the input value, and changing the value applies the correct font size.
• Automated Checks: Passed ./ninja check:svelte.