chore: versionCode 3 / 1.0.2 (v3) + 진행상황 문서 정리

- 이번 세션 적용분(외화·월별예산·전체화면모달·아코디언·계좌셀렉트·잠금유예) 정리
- 현재 상태(비공개 테스트 게시·검토통과, 테스터 opt-in 대기)로 갱신

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/app/build.gradle

@@ -15,8 +15,8 @@ android {
         applicationId "kr.sblog.slimbudget"
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode 2
-        versionName "1.0.1"
+        versionCode 3
+        versionName "1.0.2"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         aaptOptions {
              // Files and dirs to omit from the packaged assets dir, modified to accommodate modern web apps.