feat(android): AdminRequests — show requester username

Audit v2 #18. AdminRequestsScreen was showing only the request's
display name, not which user asked for it. Now fetches the admin
users list in parallel with the requests list, builds a
userId → username map, and renders "Requested by <username>"
beneath each row. Falls back to an 8-char userId prefix when the
users list fetch fails (e.g., admin without users-list access on
some future server-side ACL change).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/app/src/main/java/com/fabledsword/minstrel/admin/ui/AdminRequestsScreen.kt

@@ -81,6 +81,7 @@ fun AdminRequestsScreen(
                 )
                 is AdminRequestsUiState.Success -> RequestList(
                     rows = s.rows,
+                    usernames = s.usernames,
                     onApprove = viewModel::approve,
                     onReject = viewModel::reject,
                 )
@@ -92,12 +93,20 @@ fun AdminRequestsScreen(
 @Composable
 private fun RequestList(
     rows: List<RequestRef>,
+    usernames: Map<String, String>,
     onApprove: (String) -> Unit,
     onReject: (String) -> Unit,
 ) {
     LazyColumn(modifier = Modifier.fillMaxSize()) {
         items(items = rows, key = { it.id }) { req ->
-            AdminRequestRow(req = req, onApprove = { onApprove(req.id) }, onReject = { onReject(req.id) })
+            AdminRequestRow(
+                req = req,
+                requester = usernames[req.userId]
+                    ?: req.userId.takeIf { it.isNotEmpty() }?.take(8)
+                    ?: "unknown",
+                onApprove = { onApprove(req.id) },
+                onReject = { onReject(req.id) },
+            )
             HorizontalDivider()
         }
     }
@@ -106,6 +115,7 @@ private fun RequestList(
 @Composable
 private fun AdminRequestRow(
     req: RequestRef,
+    requester: String,
     onApprove: () -> Unit,
     onReject: () -> Unit,
 ) {
@@ -122,6 +132,13 @@ private fun AdminRequestRow(
             maxLines = 1,
             overflow = TextOverflow.Ellipsis,
         )
+        Text(
+            text = "Requested by $requester",
+            style = MaterialTheme.typography.bodySmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
         Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
             AssistChip(
                 onClick = {},

android/app/src/main/java/com/fabledsword/minstrel/admin/ui/AdminRequestsViewModel.kt

@@ -3,10 +3,13 @@ package com.fabledsword.minstrel.admin.ui
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.fabledsword.minstrel.admin.data.AdminRequestsRepository
+import com.fabledsword.minstrel.admin.data.AdminUsersRepository
 import com.fabledsword.minstrel.events.EventsStream
 import com.fabledsword.minstrel.models.RequestRef
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
@@ -19,13 +22,17 @@ private val RELEVANT_EVENT_KINDS = setOf("request.status_changed")
 sealed interface AdminRequestsUiState {
     data object Loading : AdminRequestsUiState
     data object Empty : AdminRequestsUiState
-    data class Success(val rows: List<RequestRef>) : AdminRequestsUiState
+    data class Success(
+        val rows: List<RequestRef>,
+        val usernames: Map<String, String>,
+    ) : AdminRequestsUiState
     data class Error(val message: String) : AdminRequestsUiState
 }
 
 @HiltViewModel
 class AdminRequestsViewModel @Inject constructor(
     private val repository: AdminRequestsRepository,
+    private val usersRepository: AdminUsersRepository,
     private val eventsStream: EventsStream,
 ) : ViewModel() {
 
@@ -44,11 +51,19 @@ class AdminRequestsViewModel @Inject constructor(
     fun refresh(): Job = viewModelScope.launch {
         internal.value = AdminRequestsUiState.Loading
         try {
-            val rows = repository.list()
+            val (rows, usernames) = coroutineScope {
+                val requestsJob = async { repository.list() }
+                val usernamesJob = async {
+                    runCatching {
+                        usersRepository.list().associate { it.id to it.username }
+                    }.getOrDefault(emptyMap())
+                }
+                requestsJob.await() to usernamesJob.await()
+            }
             internal.value = if (rows.isEmpty()) {
                 AdminRequestsUiState.Empty
             } else {
-                AdminRequestsUiState.Success(rows)
+                AdminRequestsUiState.Success(rows = rows, usernames = usernames)
             }
         } catch (
             @Suppress("TooGenericExceptionCaught") e: Throwable,
@@ -75,7 +90,7 @@ class AdminRequestsViewModel @Inject constructor(
             internal.value = if (filtered.isEmpty()) {
                 AdminRequestsUiState.Empty
             } else {
-                AdminRequestsUiState.Success(filtered)
+                AdminRequestsUiState.Success(rows = filtered, usernames = before.usernames)
             }
         }
         viewModelScope.launch {