feat: 匿名認証時にログインユーザーを取得できない場合エラーではなくnullを返す関数を追加

src/main/kotlin/dev/usbharu/hideout/core/infrastructure/springframework/security/LoginUserContextHolder.kt

@@ -2,4 +2,6 @@ package dev.usbharu.hideout.core.infrastructure.springframework.security
 
 interface LoginUserContextHolder {
     fun getLoginUserId(): Long
+
+    fun getLoginUserIdOrNull(): Long?
 }

src/main/kotlin/dev/usbharu/hideout/core/infrastructure/springframework/security/OAuth2JwtLoginUserContextHolder.kt

@@ -11,4 +11,13 @@ class OAuth2JwtLoginUserContextHolder : LoginUserContextHolder {
 
         return principal.getClaim<String>("uid").toLong()
     }
+
+    override fun getLoginUserIdOrNull(): Long? {
+        val principal = SecurityContextHolder.getContext()?.authentication?.principal
+        if (principal !is Jwt) {
+            return null
+        }
+
+        return principal.getClaim<String>("uid").toLongOrNull()
+    }
 }