test(webmail): keep the byte-count test ASCII (lang-lint R9)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

services/webmail/src/lib/bimiLogo.test.ts

@@ -148,7 +148,7 @@ describe("buildLogoSvg", () => {
 
   it("counts bytes, not characters", () => {
     expect(byteLength("a")).toBe(1);
-    expect(byteLength("é")).toBe(2);
+    expect(byteLength("\u00e9")).toBe(2);
   });
 });