chore: fix sass deprecation warnings and upgrade vite to 5.4

- Upgrade vite from 5.1.3 to 5.4.21 to support modern sass API option
- Configure sass preprocessor with api: 'modern' to silence legacy-js-api warning
- Silence bulma-sourced deprecation warnings (import, global-builtin, color-functions, if-function)

package.json

@@ -53,7 +53,7 @@
     "prettier": "^3.8.1",
     "sass": "^1.97.3",
     "typescript": "~5.9.3",
-    "vite": "^5.1.3",
+    "vite": "^5.4.21",
     "vite-plugin-pwa": "^0.19.0",
     "vitest": "^1.3.0",
     "vue-tsc": "^3.2.3",