feat: css editor (#1542)

* feat: allow editing CSS from settings

---------

Co-authored-by: Carlos Valente <carlosvalente@pm.me>

refactor: style tweaks

apps/server/src/api-data/assets/assets.router.ts

@@ -0,0 +1,10 @@
+import express from 'express';
+
+import { getCssOverride, postCssOverride, restoreCss } from './assets.controller.js';
+import { validatePostCss } from './assets.validation.js';
+
+export const router = express.Router();
+
+router.get('/css', getCssOverride);
+router.post('/css', validatePostCss, postCssOverride);
+router.post('/css/restore', restoreCss);