fix(android): pull-to-refresh works on Empty/Error states

Audit v2 silent-breakage: PullToRefreshBox needs scrollable content
in its nested-scroll connection to detect the gesture. Empty/Error
branches used a plain centered Column → no nested-scroll
participation → swipe gesture silently ignored → user can't recover
from a cold-load error.

Fix: re-house EmptyState inside a single-item LazyColumn with
fillParentMaxSize. Visual is identical (centered icon + title +
body) but LazyColumn participates in nested-scroll dispatch so
PullToRefreshBox fires on swipe-down.

Covers Empty + Error on every PullToRefreshScaffold-wrapped screen
(Home, Library tabs, Album/Artist/Playlist detail, Discover,
Requests, Admin*). Loading-state pull-to-refresh remains broken on
screens using per-screen LoadingCentered helpers — that's a
transient state and lower priority; separate follow-up if it
becomes a real friction.

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

android/app/src/main/java/com/fabledsword/minstrel/shared/widgets/EmptyState.kt

@@ -1,10 +1,11 @@
 package com.fabledsword.minstrel.shared.widgets
 
-import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -25,6 +26,12 @@ import com.composables.icons.lucide.Lucide
  * Per the FabledSword design system: sentence case copy, understated
  * tone. The icon defaults to Lucide's `Inbox`; callers pass their own
  * when a more topical icon helps.
+ *
+ * Renders inside a single-item LazyColumn so the widget participates
+ * in nested-scroll dispatch when wrapped by PullToRefreshBox —
+ * pull-to-refresh fires on Empty / Error states without the content
+ * actually scrolling. The fillParentMaxSize on the inner Box keeps
+ * the centered visual identical to the pre-LazyColumn layout.
  */
 @Composable
 fun EmptyState(
@@ -33,13 +40,15 @@ fun EmptyState(
     modifier: Modifier = Modifier,
     icon: ImageVector = Lucide.Inbox,
 ) {
-    Column(
+    LazyColumn(modifier = modifier.fillMaxSize()) {
-        modifier = modifier
+        item {
-            .fillMaxSize()
+            Box(
+                modifier = Modifier
+                    .fillParentMaxSize()
                     .padding(32.dp),
-        verticalArrangement = Arrangement.Center,
+                contentAlignment = Alignment.Center,
-        horizontalAlignment = Alignment.CenterHorizontally,
             ) {
+                Column(horizontalAlignment = Alignment.CenterHorizontally) {
                     Icon(
                         imageVector = icon,
                         contentDescription = null,
@@ -61,4 +70,7 @@ fun EmptyState(
                         textAlign = TextAlign.Center,
                     )
                 }
+            }
+        }
+    }
 }