chore: Move from inline-css -> css-inline (#6252)

server/models/helpers/HTMLHelper.ts

@@ -0,0 +1,20 @@
+import { inline } from "css-inline";
+import env from "@server/env";
+
+export default class HTMLHelper {
+  /**
+   * Move CSS styles from <style> tags to inline styles with default settings.
+   *
+   * @param html The HTML to inline CSS styles for.
+   * @returns The HTML with CSS styles inlined.
+   */
+  public static inlineCSS(html: string): string {
+    return inline(html, {
+      base_url: env.URL,
+      inline_style_tags: true,
+      keep_link_tags: false,
+      keep_style_tags: false,
+      load_remote_stylesheets: false,
+    });
+  }
+}