Fix jumbo emoji detection broken by production minifier.

Replace surrogate-pair emoji regex with Unicode property escapes so Rolldown no longer corrupts matching in production builds.

src/app/plugins/react-custom-html-parser.tsx

@@ -31,7 +31,7 @@ import {
   mxcUrlToHttp,
 } from '../utils/matrix';
 import { getMemberDisplayName } from '../utils/room';
-import { EMOJI_PATTERN, sanitizeForRegex, URL_NEG_LB } from '../utils/regex';
+import { EMOJI_REG_G, sanitizeForRegex } from '../utils/regex';
 import { getHexcodeForEmoji, getShortcodeFor } from './emoji';
 import { findAndReplace } from '../utils/findAndReplace';
 import {
@@ -48,8 +48,6 @@ import { openExternalUrl } from '../utils/tauri';
 
 const ReactPrism = lazy(() => import('./react-prism/ReactPrism'));
 
-const EMOJI_REG_G = new RegExp(`${URL_NEG_LB}(${EMOJI_PATTERN})`, 'g');
-
 /**
  * Click handler for external links - uses Tauri shell on desktop/mobile
  */