Show latest credit ledger in admin

Expose a paginated global ledger timeline and load it automatically so operators can see recent credit activity without first locating a user.

src/main/kotlin/com/osglab/account/features/admin/routes/AdminRoutes.kt

@@ -237,6 +237,33 @@ fun Route.adminApiRoutes(
             }
         }
 
+        get("/credits/ledger") {
+            if (
+                call.requireRole(
+                    sessionService,
+                    setOf(AdminRole.SUPER_ADMIN, AdminRole.SUPPORT),
+                ) == null
+            ) return@get
+            val limit = call.pageLimit(maximum = 100, default = 100) ?: run {
+                call.respond(HttpStatusCode.BadRequest, AdminErrorResponse("VALIDATION_ERROR"))
+                return@get
+            }
+            try {
+                val page = usersService.latestLedger(
+                    limit = limit,
+                    cursor = call.request.queryParameters["cursor"],
+                )
+                call.respond(
+                    PageResponse(
+                        page.items.map(AdminUserLedgerEntryDto::toLedgerResponse),
+                        page.nextCursor,
+                    ),
+                )
+            } catch (_: IllegalArgumentException) {
+                call.respond(HttpStatusCode.BadRequest, AdminErrorResponse("VALIDATION_ERROR"))
+            }
+        }
+
         post("/credits/grants") {
             val principal = call.requireMutationPrincipal(config, sessionService) ?: return@post
             if (principal.role != AdminRole.SUPER_ADMIN) {
@@ -667,6 +694,7 @@ private fun AdminUserDetailDto.toUserDetailResponse(): AdminUserDetailResponse =
 private fun AdminUserLedgerEntryDto.toLedgerResponse(): AdminLedgerResponse =
     AdminLedgerResponse(
         entryId = id,
+        userId = userId,
         type = when (type) {
             "USAGE_RESERVE" -> "reserve"
             "USAGE_SETTLE" -> "settle"
@@ -864,6 +892,7 @@ private data class AdminUserDetailResponse(
 @Serializable
 private data class AdminLedgerResponse(
     val entryId: String,
+    val userId: String,
     val type: String,
     val amount: Long,
     val balanceAfter: Long,

src/main/kotlin/com/osglab/account/features/admin/users/models/AdminUserDtos.kt

@@ -26,6 +26,7 @@ data class AdminUserPageDto(
 @Serializable
 data class AdminUserLedgerEntryDto(
     val id: String,
+    val userId: String,
     val type: String,
     val amountDelta: Long,
     val balanceAfter: Long,

src/main/kotlin/com/osglab/account/features/admin/users/repositories/AdminUsersRepository.kt

@@ -47,6 +47,11 @@ interface AdminUsersRepository {
         limit: Int,
         cursor: AdminUserLedgerCursor?,
     ): List<AdminUserLedgerEntryDto>
+
+    suspend fun listLatestLedger(
+        limit: Int,
+        cursor: AdminUserLedgerCursor?,
+    ): List<AdminUserLedgerEntryDto>
 }
 
 class ExposedAdminUsersRepository(
@@ -173,6 +178,28 @@ class ExposedAdminUsersRepository(
             .limit(limit)
             .map { it.toUserLedgerRow().toDto() }
     }
+
+    override suspend fun listLatestLedger(
+        limit: Int,
+        cursor: AdminUserLedgerCursor?,
+    ): List<AdminUserLedgerEntryDto> = databaseFactory.query {
+        val query = AdminUsersCreditLedgerTable.selectAll()
+        if (cursor != null) {
+            query.where {
+                (AdminUsersCreditLedgerTable.createdAt less cursor.createdAt) or
+                    (
+                        (AdminUsersCreditLedgerTable.createdAt eq cursor.createdAt) and
+                            (AdminUsersCreditLedgerTable.id less cursor.ledgerEntryId.toString())
+                        )
+            }
+        }
+        query.orderBy(
+            AdminUsersCreditLedgerTable.createdAt to SortOrder.DESC,
+            AdminUsersCreditLedgerTable.id to SortOrder.DESC,
+        )
+            .limit(limit)
+            .map { it.toUserLedgerRow().toDto() }
+    }
 }
 
 private data class UserSupportRows(
@@ -324,6 +351,7 @@ private fun ResultRow.toUserLedgerRow() = UserLedgerRow(
 
 private fun UserLedgerRow.toDto() = AdminUserLedgerEntryDto(
     id = id.toString(),
+    userId = userId.toString(),
     type = type.name,
     amountDelta = amountDelta,
     balanceAfter = balanceAfter,

src/main/kotlin/com/osglab/account/features/admin/users/services/AdminUsersService.kt

@@ -1,6 +1,7 @@
 package com.osglab.account.features.admin.users.services
 
 import com.osglab.account.features.admin.users.models.AdminUserDetailDto
+import com.osglab.account.features.admin.users.models.AdminUserLedgerEntryDto
 import com.osglab.account.features.admin.users.models.AdminUserLedgerPageDto
 import com.osglab.account.features.admin.users.models.AdminUserPageDto
 import com.osglab.account.features.admin.users.repositories.AdminUserCursor
@@ -67,11 +68,27 @@ class AdminUsersService(
         userId: UUID,
         limit: Int = 50,
         cursor: String? = null,
+    ): AdminUserLedgerPageDto {
+        return ledgerPage(limit, cursor) { pageSize, decodedCursor ->
+            if (!repository.exists(userId)) throw AdminUserNotFoundException()
+            repository.listLedger(userId, pageSize, decodedCursor)
+        }
+    }
+
+    suspend fun latestLedger(
+        limit: Int = 100,
+        cursor: String? = null,
+    ): AdminUserLedgerPageDto =
+        ledgerPage(limit, cursor, repository::listLatestLedger)
+
+    private suspend fun ledgerPage(
+        limit: Int,
+        cursor: String?,
+        load: suspend (Int, AdminUserLedgerCursor?) -> List<AdminUserLedgerEntryDto>,
     ): AdminUserLedgerPageDto {
         require(limit in 1..100) { "Ledger page limit must be between 1 and 100" }
         val decodedCursor = cursor?.let(AdminUserLedgerCursorCodec::decode)
-        if (!repository.exists(userId)) throw AdminUserNotFoundException()
-        val results = repository.listLedger(userId, limit + 1, decodedCursor)
+        val results = load(limit + 1, decodedCursor)
         val hasMore = results.size > limit
         val items = results.take(limit)
         val nextCursor = if (hasMore) {