message: fixup! Mention processing: use \b to match word boundaries.
diff: @@ -147,7 +147,7 @@ export class MatrixAction {
  `<a href="https://matrix.to/#/${userId}">`+
  `${ircFormatting.escapeHtmlChars(identifier)}</a>`
  );
  - this.text = this.text.replace(regex, `$1${identifier}`);
  + this.text = this.text.replace(regex, `${identifier}`);
  // Don't match this name twice, we've already replaced all entries.
  matched.add(matchName.toLowerCase());
  }
  