fix(android): cosmetic cleanup — admin badge, AdminLanding subtitle, NowPlaying clip

Three small audit v3 cleanups bundled:

* Bug-6 / §4.19 — AdminLanding Users card subtitle was stale
  ("Manage accounts") even though Invites shipped weeks ago.
  Now: "Manage accounts and invites" to match Flutter.

* §4.22 — Account card never showed the admin badge. Flutter
  appends " · admin" next to the username when isAdmin. Threaded
  isAdmin through AccountCard and added the suffix.

* Bug-4 — NowPlayingBody used Column.Center with no scroll, so on
  small-portrait or any landscape phone the cover + scrubber +
  transport + actions row clip. Added verticalScroll so users on
  small screens can scroll the body instead of losing affordances.

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

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

@@ -177,7 +177,7 @@ private fun SectionList(counts: AdminCounts, navController: NavHostController) {
             SectionCard(
                 icon = Lucide.Users,
                 title = "Users",
-                subtitle = "Manage accounts",
+                subtitle = "Manage accounts and invites",
                 count = counts.users,
                 onClick = { navController.navigate(AdminUsers) },
             )

android/app/src/main/java/com/fabledsword/minstrel/player/ui/NowPlayingScreen.kt

@@ -4,6 +4,8 @@ package com.fabledsword.minstrel.player.ui
 
 import androidx.compose.animation.ExperimentalSharedTransitionApi
 import androidx.compose.foundation.background
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -211,6 +213,7 @@ private fun NowPlayingBody(
         modifier = Modifier
             .fillMaxSize()
             .padding(inner)
+            .verticalScroll(rememberScrollState())
             .padding(horizontal = 24.dp),
         verticalArrangement = Arrangement.Center,
         horizontalAlignment = Alignment.CenterHorizontally,

android/app/src/main/java/com/fabledsword/minstrel/settings/ui/SettingsScreen.kt

@@ -93,7 +93,11 @@ fun SettingsScreen(
                 .padding(16.dp),
             verticalArrangement = Arrangement.spacedBy(16.dp),
         ) {
-            AccountCard(username = state.username, serverUrl = state.serverUrl)
+            AccountCard(
+                username = state.username,
+                isAdmin = state.isAdmin,
+                serverUrl = state.serverUrl,
+            )
             NavTile(
                 icon = Lucide.ListMusic,
                 title = "My requests",
@@ -163,7 +167,7 @@ private fun NavTile(
 }
 
 @Composable
-private fun AccountCard(username: String, serverUrl: String) {
+private fun AccountCard(username: String, isAdmin: Boolean, serverUrl: String) {
     ElevatedCard(modifier = Modifier.fillMaxWidth()) {
         Column(
             modifier = Modifier.padding(16.dp),
@@ -174,8 +178,12 @@ private fun AccountCard(username: String, serverUrl: String) {
                 style = MaterialTheme.typography.titleMedium,
                 color = MaterialTheme.colorScheme.onSurface,
             )
+            val adminTag = if (isAdmin) " · admin" else ""
             Text(
-                text = if (username.isEmpty()) "Signed in" else "Signed in as $username",
+                text = when {
+                    username.isEmpty() -> "Signed in"
+                    else -> "Signed in as $username$adminTag"
+                },
                 style = MaterialTheme.typography.bodyMedium,
                 color = MaterialTheme.colorScheme.onSurfaceVariant,
             )