test(android): run the sync pass in the test body, not through init's background collector (#5654)

advanceUntilIdle does not count backgroundScope work as pending, so the
pass init would start never ran. The network state is Offline so
construction starts none, and each test calls syncSafe itself and asserts
lastSyncError stays null.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/app/src/test/java/com/fabledsword/minstrel/cache/sync/SyncControllerTest.kt

@@ -22,6 +22,7 @@ import org.junit.jupiter.api.Test
 import retrofit2.Response
 import retrofit2.Retrofit
 import kotlin.test.assertEquals
+import kotlin.test.assertNull
 
 /**
  * The server returns at most 1000 changes a call (#5654). One page per
@@ -38,7 +39,8 @@ class SyncControllerTest {
         every { sessionCookie } returns MutableStateFlow(null)
     }
     private val networkStatus: NetworkStatusController = mockk {
-        every { state } returns MutableStateFlow(ServerHealth.Healthy)
+        // Offline, so construction starts no pass; each test runs one itself.
+        every { state } returns MutableStateFlow(ServerHealth.Offline)
     }
 
     // The cursor round-trips through the DAO, so it is held for real.
@@ -59,11 +61,13 @@ class SyncControllerTest {
         coEvery { api.sync(1000) } returns page(2000, deletedTracks = listOf("merged-away"))
         coEvery { api.sync(2000) } returns noContent()
 
-        SyncController(
+        val controller = SyncController(
             metadataDao, mockk<CachedArtistDao>(relaxed = true), mockk<CachedAlbumDao>(relaxed = true),
             trackDao, authStore, backgroundScope, networkStatus, retrofit,
         )
-        testScheduler.advanceUntilIdle()
+        controller.syncSafe()
+
+        assertNull(controller.lastSyncError.value)
 
         coVerify(exactly = 1) { api.sync(2000) }
         coVerify { trackDao.deleteByIds(listOf("merged-away")) }
@@ -75,11 +79,13 @@ class SyncControllerTest {
         stored = SyncMetadataEntity(cursor = 500)
         coEvery { api.sync(500) } returns page(500)
 
-        SyncController(
+        val controller = SyncController(
             metadataDao, mockk<CachedArtistDao>(relaxed = true), mockk<CachedAlbumDao>(relaxed = true),
             trackDao, authStore, backgroundScope, networkStatus, retrofit,
         )
-        testScheduler.advanceUntilIdle()
+        controller.syncSafe()
+
+        assertNull(controller.lastSyncError.value)
 
         coVerify(exactly = 1) { api.sync(500) }
     }
@@ -91,11 +97,13 @@ class SyncControllerTest {
         coEvery { api.sync(0) } returns page(1000)
         coEvery { api.sync(1000) } returns noContent()
 
-        SyncController(
+        val controller = SyncController(
             metadataDao, mockk<CachedArtistDao>(relaxed = true), mockk<CachedAlbumDao>(relaxed = true),
             trackDao, authStore, backgroundScope, networkStatus, retrofit,
         )
-        testScheduler.advanceUntilIdle()
+        controller.syncSafe()
+
+        assertNull(controller.lastSyncError.value)
 
         coVerify(exactly = 1) { api.sync(1000) }
         assertEquals(1000L, stored?.cursor)