fix: TypeScript 빌드 에러 수정 (#17)

- DashboardPage: 미사용 변수 i 제거 (TS6133)
- PlatformStatusIndicator: CredentialStatus 타입 내로잉 적용 (TS7053)

Closes #17

react/src/features/dashboard/pages/DashboardPage.tsx

@@ -77,7 +77,7 @@ function randomMessages() {
   const statuses = ["완료", "완료", "완료", "실패", "진행", "예약"] as const;
   const hours = ["09:00", "09:15", "10:30", "11:00", "14:00", "15:30", "18:00", "20:00"];
 
-  return Array.from({ length: 5 }, (_, i) => ({
+  return Array.from({ length: 5 }, () => ({
     template: templates[rand(0, templates.length - 1)],
     targetCount: fmt(rand(1, 50000)),
     status: statuses[rand(0, statuses.length - 1)],

react/src/features/service/components/PlatformStatusIndicator.tsx

@@ -67,7 +67,7 @@ export default function PlatformStatusIndicator({
           <AppleLogo className="w-3.5 h-3.5" />
         )}
       </span>
-      {hasIssue && credential.credentialStatus && (
+      {hasIssue && (credential.credentialStatus === "warn" || credential.credentialStatus === "error") && (
         <>
           <span
             className={`absolute -top-1 -right-1 size-2.5 rounded-full border-2 border-white ${DOT_STYLES[credential.credentialStatus]}`}