[CC Projects] Lines are sometimes off by one line

[create-issue-branch]

Status

closes #1259, #1253

What's changed

• Remove border on code output blocks
• Fix alignment of line numbers in code blocks by
  • Using variables to set fonts consistently in the interface
  • Fixing line spacing in a number of spots using the typography mixins supplied by the design system.

This also unifies the list of fonts used in the Editor to the list in settings/fonts. They can be added-to/changed by setting --editor-font-family-sans-serif and --editor-font-family-monospace.

Screenshots

Problem	Before	After
Emojis breaking highligting
Another example
Fixes border on output

[Copilot]

Pull Request Overview

This PR fixes line number alignment issues in code blocks throughout the editor by standardizing font usage and applying consistent typography styles. The changes address problems where emojis and other content would cause line highlighting to misalign, and removes an unwanted border from code output blocks.

Key changes:

• Centralized font family definitions in a new _fonts.scss file with CSS custom properties for consistent font application
• Applied design system typography mixins to ensure consistent line spacing across code blocks and instruction panels
• Removed border styling from code output blocks in the instructions panel

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/assets/stylesheets/settings/_fonts.scss	New file defining standardized sans-serif and monospace font stacks
src/assets/stylesheets/index.scss	Migrated to use centralized font variables via CSS custom properties
src/assets/stylesheets/InternalStyles.scss	Added font variable definitions with fallbacks for web component customization
src/assets/stylesheets/Instructions.scss	Applied typography mixins for consistent line spacing and removed border from code output
src/assets/stylesheets/EditorPanel.scss	Applied typography mixin to code editor scroller for consistent line height
src/assets/stylesheets/Button.scss	Updated to use centralized sans-serif font variable
src/assets/stylesheets/AstroPiModel.scss	Updated to use centralized monospace font variable
src/assets/stylesheets/App.scss	Updated to use centralized sans-serif font variable
CHANGELOG.md	Documented new features and fixed issues

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[loiswells97]

My only concern with this is that it might change the fonts we're using in places like within codemirror, as we were using different monospace fonts in different places - maybe that's okay though?

[loiswells97]

Just a few thoughts/questions