fix(font): Add Sindhi-specific CSS for font clarity (@Shamsuddin45)

[Shamsuddin45]

Add language-specific CSS for Sindhi language font clarity.

Description

Checks

• Adding quotes?
  • Make sure to follow the quotes documentation
  • Make sure to include translations for the quotes in the description (or another comment) so we can verify their content.
• Adding a language?
  • Make sure to follow the languages documentation
  • Add language to packages/schemas/src/languages.ts
  • Add language to exactly one group in frontend/src/ts/constants/languages.ts
  • Add language json file to frontend/static/languages
• Adding a theme?
  • Make sure to follow the themes documentation
  • Add theme to packages/schemas/src/themes.ts
  • Add theme to frontend/src/ts/constants/themes.ts
  • (optional) Add theme css file to frontend/static/themes
  • Add some screenshots of the theme, especially with different test settings (colorful, flip colors) to your pull request
• Adding a layout?
  • Make sure to follow the layouts documentation
  • Add layout to packages/schemas/src/layouts.ts
  • Add layout json file to frontend/static/layouts
• Adding a font?
  • Make sure to follow the fonts documentation
  • Add font file to frontend/static/webfonts
  • Add font to packages/schemas/src/fonts.ts
  • Add font to frontend/src/ts/constants/fonts.ts
• Check if any open issues are related to this PR; if so, be sure to tag them below.
• Make sure the PR title follows the Conventional Commits standard. (https://www.conventionalcommits.org for more info)
• Make sure to include your GitHub username prefixed with @ inside parentheses at the end of the PR title.

Closes #

[fehmer]

hi, why is this needed. what makes sindhi different to other languages with joiningScript?

[Shamsuddin45]

hi, why is this needed. what makes sindhi different to other languages with joiningScript?

Thanks for pointing that out.

I noticed this specifically while testing the Sindhi language. With the default font and letter spacing, some Sindhi words were rendered incorrectly because certain joining characters appeared disconnected. Applying letter-spacing: normal together with a font that properly supports Sindhi (e.g. Noto Sans Arabic/Lateef) fixed the rendering.

I haven't yet verified whether the same issue affects all other joiningScript languages, so I scoped the change to Sindhi to avoid changing typography for languages I hadn't tested.