feat(font): add Kanit and Sarabun (@JNX03) (monkeytypegame#6500)

### Description

<!-- Please describe the change(s) made in your PR -->

- Imported `Kanit-Regular.woff2` and `Sarabun-Bold.woff` into the
project’s webfonts directory.
- Updated `frontend/static/fonts/_list.json` to register the new fonts
under “availableFonts.”
- Modified `frontend/src/styles/fonts.scss` to include `@font-face`
declarations for both Kanit Regular and Sarabun Bold, with appropriate
`font-family`, `font-weight`, and `font-style` settings.

---

### Checks

- [ ] Adding quotes?  
- [ ] Make sure to include translations for the quotes in the
description (or another comment) so we can verify their content.
- [ ] Adding a language or a theme?  
- [ ] If it’s a language, did you edit `_list.json`, `_groups.json` and
add `languages.json`?
  - [ ] If it’s a theme, did you add the theme.css?  
- Also please add a screenshot of the theme, it would be extra awesome
if you do so!
- [ ] Check if any open issues are related to this PR; if so, be sure to
tag them below.
- [x] Make sure the PR title follows the Conventional Commits standard.
(https://www.conventionalcommits.org/ for more info)
- [x] Make sure to include your GitHub username prefixed with `@` inside
parentheses at the end of the PR title.

---------

Co-authored-by: Miodec <[email protected]>

Author: JNX03

frontend/src/styles/fonts.scss

@@ -98,6 +98,12 @@ $fonts: (
   "Geist": (
     "src": "Geist-Medium",
   ),
+  "Kanit": (
+    "src": "Kanit-Regular",
+  ),
+  "Sarabun": (
+    "src": "Sarabun-Bold",
+  ),
   "Geist Mono": (
     "src": "GeistMono-Medium",
   ),

frontend/static/fonts/_list.json

@@ -106,6 +106,12 @@
   {
     "name": "Geist"
   },
+  {
+    "name": "Sarabun"
+  },
+  {
+    "name": "Kanit"
+  },
   {
     "name": "Geist Mono"
   }