Ten screens duplicated the same TopAppBar + Text(title) +
optional-back-arrow + MainAppBarActions sandwich. Extract into
MinstrelTopAppBar(title, navController, currentRouteName, onBack,
actions) at shared/widgets/. Library's tab row still composes
above it inside a Column; Library's Shuffle button slots into the
extra actions trailing-lambda; drill-down screens pass onBack for
the back arrow; root tabs leave onBack null.
Net: -48 lines across 10 screens, +50 lines for the helper.
SearchScreen keeps its own TopAppBar (title is a SearchField
composable, not a string).
Per-screen TrackActionsViewModel snackbar wiring (Library/Search/
detail screens) was intentionally NOT consolidated here: each
hiltViewModel() returns a different VM instance than the shell-
scoped one already in ShellScaffold, so dedup belongs in 3c
(shell-scope the VM via CompositionLocal) rather than freezing the
current duplicate into a helper.
bvandeusen
02a6c45958