feat: SMS 스캔 패키지를 flutter_sms_inbox로 변경 및 플랫폼별 최적화

- telephony 패키지를 flutter_sms_inbox로 교체
- 플랫폼별 SMS 스캔 로직 구현:
  * Web: mock data 사용
  * Android: flutter_sms_inbox로 실제 SMS 스캔
  * iOS: SMS 기능 비활성화
- iOS에서 SMS 스캔 버튼 숨김 처리
- PlatformHelper 유틸리티 추가로 웹 환경 오류 해결
- Android 네이티브 MethodChannel 코드 제거

pubspec.lock

@@ -432,14 +432,14 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.1.2"
-  flutter_sms:
+  flutter_sms_inbox:
     dependency: "direct main"
     description:
-      name: flutter_sms
-      sha256: "2fe5f584f02596343557eeca56348f9b82413fefe83a423fab880cdbdf54d8d8"
+      name: flutter_sms_inbox
+      sha256: "50580e4265ab65b128777ea3db9b0286ef7beff12df644de42643b26e8b76ee5"
       url: "https://pub.dev"
     source: hosted
-    version: "2.3.3"
+    version: "1.0.4"
   flutter_svg:
     dependency: "direct main"
     description:
@@ -1143,14 +1143,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "3.3.1"
-  telephony:
-    dependency: "direct main"
-    description:
-      name: telephony
-      sha256: "821e074acec3c611e48edadd50a6d9fef864943771a545da7924adcc8509ada9"
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.2.0"
   term_glyph:
     dependency: transitive
     description: