fix(android): split MinstrelNavGraph into NavGraphBuilder extensions

detekt LongMethod (97/60 lines). Body had no actual logic — just 13
sequential composable<T>() route declarations. Split by route category
(matches the existing comment headers):

  - inShellTopLevel(navController, expandPlayer) — 8 in-shell tabs
  - inShellDetail(expandPlayer) — 6 push-on-top detail screens
  - outsideShell() — NowPlaying (with slide-up transitions), Queue,
    ServerUrl, Login

`MinstrelNavGraph` itself is now 15 lines (NavHost shell that delegates
to the three groups), and each helper sits well under the 60-line cap.

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

android/app/src/main/java/com/fabledsword/minstrel/nav/MinstrelNavGraph.kt

@@ -5,6 +5,7 @@ import androidx.compose.animation.slideOutVertically
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.navigation.NavGraphBuilder
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.NavHost
 import androidx.navigation.compose.composable
@@ -28,123 +29,115 @@ fun MinstrelNavGraph(
     modifier: Modifier = Modifier,
 ) {
     val expandPlayer = { navController.navigate(NowPlaying) }
-
     NavHost(
         navController = navController,
         startDestination = Library,
         modifier = modifier.fillMaxSize(),
     ) {
-        // ── In-shell top-level destinations ───────────────────────────
+        inShellTopLevel(navController, expandPlayer)
+        inShellDetail(expandPlayer)
+        outsideShell()
+    }
+}
 
-        composable<Home> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Home", "Lands in the next design-drift sub-task.")
-            }
-        }
-
-        composable<Library> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                LibraryScreen(navController = navController)
-            }
-        }
-
-        composable<Search> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Search", "Lands in a later phase.")
-            }
-        }
-
-        composable<Discover> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Discover", "Lands in Phase 10 (Lidarr requests).")
-            }
-        }
-
-        composable<Playlists> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Playlists", "Lands in Phase 7.")
-            }
-        }
-
-        composable<Settings> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Settings", "Lands in Phase 11.")
-            }
-        }
-
-        composable<Admin> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Admin", "Admin landing — lands in a later phase.")
-            }
-        }
-
-        composable<Requests> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Requests", "Your Lidarr requests — Phase 10.")
-            }
-        }
-
-        // ── In-shell detail screens (push-on-top) ─────────────────────
-
-        composable<AlbumDetail> { backStackEntry ->
-            val route: AlbumDetail = backStackEntry.toRoute()
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Album", "Album detail for ${route.id} — later 5.x slice.")
-            }
-        }
-
-        composable<ArtistDetail> { backStackEntry ->
-            val route: ArtistDetail = backStackEntry.toRoute()
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Artist", "Artist detail for ${route.id} — later 5.x slice.")
-            }
-        }
-
-        composable<PlaylistDetail> { backStackEntry ->
-            val route: PlaylistDetail = backStackEntry.toRoute()
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Playlist", "Playlist detail for ${route.id} — Phase 7.")
-            }
-        }
-
-        composable<AdminRequests> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Admin · Requests", "Lands with admin slice.")
-            }
-        }
-        composable<AdminQuarantine> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Admin · Quarantine", "Lands with admin slice.")
-            }
-        }
-        composable<AdminUsers> {
-            ShellScaffold(onExpandPlayer = expandPlayer) {
-                ComingSoon("Admin · Users", "Lands with admin slice.")
-            }
-        }
-
-        // ── Outside-shell full-screen routes ──────────────────────────
-
-        composable<NowPlaying>(
-            // Slide up from the bottom on enter; back down on dismiss.
-            // Mirrors the Flutter CustomTransitionPage (280ms easeOutCubic).
-            enterTransition = { slideInVertically(initialOffsetY = { it }) },
-            exitTransition = { slideOutVertically(targetOffsetY = { it }) },
-            popEnterTransition = { slideInVertically(initialOffsetY = { it }) },
-            popExitTransition = { slideOutVertically(targetOffsetY = { it }) },
-        ) {
-            NowPlayingScreen()
-        }
-
-        composable<Queue> { ComingSoon("Queue", "Lands in a later 6.x slice.") }
-
-        composable<ServerUrl> {
-            ComingSoon("Connect to your Minstrel", "Server-URL entry — Phase 11.")
-        }
-        composable<Login> {
-            ComingSoon("Sign in", "Login flow — Phase 11.")
+private fun NavGraphBuilder.inShellTopLevel(
+    navController: NavHostController,
+    expandPlayer: () -> Unit,
+) {
+    composable<Home> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Home", "Lands in the next design-drift sub-task.")
         }
     }
+    composable<Library> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            LibraryScreen(navController = navController)
+        }
+    }
+    composable<Search> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Search", "Lands in a later phase.")
+        }
+    }
+    composable<Discover> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Discover", "Lands in Phase 10 (Lidarr requests).")
+        }
+    }
+    composable<Playlists> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Playlists", "Lands in Phase 7.")
+        }
+    }
+    composable<Settings> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Settings", "Lands in Phase 11.")
+        }
+    }
+    composable<Admin> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Admin", "Admin landing — lands in a later phase.")
+        }
+    }
+    composable<Requests> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Requests", "Your Lidarr requests — Phase 10.")
+        }
+    }
+}
+
+private fun NavGraphBuilder.inShellDetail(expandPlayer: () -> Unit) {
+    composable<AlbumDetail> { backStackEntry ->
+        val route: AlbumDetail = backStackEntry.toRoute()
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Album", "Album detail for ${route.id} — later 5.x slice.")
+        }
+    }
+    composable<ArtistDetail> { backStackEntry ->
+        val route: ArtistDetail = backStackEntry.toRoute()
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Artist", "Artist detail for ${route.id} — later 5.x slice.")
+        }
+    }
+    composable<PlaylistDetail> { backStackEntry ->
+        val route: PlaylistDetail = backStackEntry.toRoute()
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Playlist", "Playlist detail for ${route.id} — Phase 7.")
+        }
+    }
+    composable<AdminRequests> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Admin · Requests", "Lands with admin slice.")
+        }
+    }
+    composable<AdminQuarantine> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Admin · Quarantine", "Lands with admin slice.")
+        }
+    }
+    composable<AdminUsers> {
+        ShellScaffold(onExpandPlayer = expandPlayer) {
+            ComingSoon("Admin · Users", "Lands with admin slice.")
+        }
+    }
+}
+
+private fun NavGraphBuilder.outsideShell() {
+    composable<NowPlaying>(
+        // Slide up from the bottom on enter; back down on dismiss.
+        // Mirrors the Flutter CustomTransitionPage (280ms easeOutCubic).
+        enterTransition = { slideInVertically(initialOffsetY = { it }) },
+        exitTransition = { slideOutVertically(targetOffsetY = { it }) },
+        popEnterTransition = { slideInVertically(initialOffsetY = { it }) },
+        popExitTransition = { slideOutVertically(targetOffsetY = { it }) },
+    ) {
+        NowPlayingScreen()
+    }
+    composable<Queue> { ComingSoon("Queue", "Lands in a later 6.x slice.") }
+    composable<ServerUrl> {
+        ComingSoon("Connect to your Minstrel", "Server-URL entry — Phase 11.")
+    }
+    composable<Login> { ComingSoon("Sign in", "Login flow — Phase 11.") }
 }
 
 @Composable