test(country-fixture): 강제 국가 매핑 판별 함수와 회귀 테스트를 추가한다

src/test/kotlin/kr/co/vividnext/sodalive/support/CountryMemberFixtures.kt

@@ -0,0 +1,10 @@
+package kr.co.vividnext.sodalive.support
+
+import kr.co.vividnext.sodalive.member.Member
+import kr.co.vividnext.sodalive.member.contentpreference.resolveCountryCodeWithForcedMapping
+
+// Fixture selection only: two distinct headers detect forced countries without copying member IDs.
+internal fun Member.hasForcedCountryMapping(): Boolean {
+    return resolveCountryCodeWithForcedMapping(this, "KR") != "KR" ||
+        resolveCountryCodeWithForcedMapping(this, "JP") != "JP"
+}

src/test/kotlin/kr/co/vividnext/sodalive/support/CountryMemberFixturesTest.kt

@@ -0,0 +1,22 @@
+package kr.co.vividnext.sodalive.support
+
+import kr.co.vividnext.sodalive.member.Member
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.params.ParameterizedTest
+import org.junit.jupiter.params.provider.CsvSource
+
+class CountryMemberFixturesTest {
+    @ParameterizedTest
+    @CsvSource("16, true", "17958, true", "29721, true", "100, false")
+    @DisplayName("일반 회원 fixture는 강제 국가 매핑 회원과 기존 목록에서 누락된 회원을 제외한다")
+    fun shouldIdentifyForcedCountryMappingsForFixtureSelection(memberId: Long, expected: Boolean) {
+        val member = Member(
+            email = "member$memberId@test.com",
+            password = "password",
+            nickname = "member$memberId"
+        ).apply { id = memberId }
+
+        assertEquals(expected, member.hasForcedCountryMapping())
+    }
+}