fix(nav): recovery back-stack loop + the Today tab's inconsistent back arrow

Two navigation fixes, one found the expensive way.

1. Post-recovery BACK bounced users to the Recovery screen, forever. The Home
   entry that routed to Recovery stayed on the back stack holding
   needsRecovery=true, and its LaunchedEffect re-fires whenever the entry is
   returned to — so after a successful recovery, BACK landed on stale-Home,
   which instantly redirected to Recovery again. It looks EXACTLY like the
   couple key was lost again (it wasn't; verified: the keyset survives process
   kill and cold-starts straight to Home). Cost an hour of key-loss ghost
   hunting live before the process-alive evidence gave it away. onRecovered and
   the partner-restore onDone now popUpTo(HOME) INCLUSIVE + launchSingleTop —
   the stale entry is replaced, not buried; BACK from Home exits the app like
   every other root tab. C-NAV-002 class; the restore variant was worse (it
   left Home AND Recovery underneath).

2. C-TODAY-BACK-001 (open P3 from the report): the Today tab drew a back arrow
   the other four tabs don't. DAILY_QUESTION is a bottom-nav tab — the bar IS
   the navigation. onBack is now nullable-defaulting-null and the nav wiring
   passes none; LocalQuestionContent already renders the arrow only when
   non-null. Verified live: no arrow, other tabs unchanged.

Suite green, verified on-device (BACK exits; Today clean).

app/src/main/java/app/closer/core/navigation/AppNavigation.kt

@@ -268,7 +268,9 @@ fun AppNavigation(
                 route = AppRoute.DAILY_QUESTION,
                 deepLinks = listOf(navDeepLink { uriPattern = "closer://closer.app/daily_question" })
             ) {
-                DailyQuestionScreen(onNavigate = navigateRoute, onBack = navigateBackOrHome)
+                // No onBack: it's a bottom-nav tab (C-TODAY-BACK-001 — the arrow made Today
+                // inconsistent with the other four tabs, whose bar IS the navigation).
+                DailyQuestionScreen(onNavigate = navigateRoute)
             }
             composable(route = AppRoute.QUESTION_PACKS) {
                 QuestionPackLibraryScreen(onNavigate = navigateRoute)
@@ -409,8 +411,14 @@ fun AppNavigation(
             composable(route = AppRoute.RECOVERY) {
                 RecoveryScreen(
                     onRecovered = {
+                        // Pop up to and INCLUDING the old HOME, not just Recovery: the Home entry that
+                        // routed here still holds needsRecovery=true, and its LaunchedEffect re-fires
+                        // whenever it's returned to — so BACK from the new Home bounced users straight
+                        // back to Recovery, forever, looking exactly like the key had been lost again
+                        // (C-NAV-002 class; cost an hour of key-loss ghost-hunting live).
                         navController.navigate(AppRoute.HOME) {
-                            popUpTo(AppRoute.RECOVERY) { inclusive = true }
+                            popUpTo(AppRoute.HOME) { inclusive = true }
+                            launchSingleTop = true
                         }
                     },
                     onPartnerRestore = { navController.navigate(AppRoute.RESTORE_REQUEST) }
@@ -421,8 +429,11 @@ fun AppNavigation(
             composable(route = AppRoute.RESTORE_REQUEST) {
                 RestoreRequestScreen(
                     onDone = {
+                        // Same stale-Home disease as onRecovered above — and worse: popping only this
+                        // screen left BOTH the stale Home and the Recovery entry underneath.
                         navController.navigate(AppRoute.HOME) {
-                            popUpTo(AppRoute.RESTORE_REQUEST) { inclusive = true }
+                            popUpTo(AppRoute.HOME) { inclusive = true }
+                            launchSingleTop = true
                         }
                     },
                     onBack = navigateBackOrHome

app/src/main/java/app/closer/ui/questions/DailyQuestionScreen.kt

@@ -11,7 +11,10 @@ import app.closer.domain.model.Question
 @Composable
 fun DailyQuestionScreen(
     onNavigate: (String) -> Unit = {},
-    onBack: () -> Unit = {},
+    // Nullable, defaulting to none: DAILY_QUESTION is a bottom-nav TAB, and the bar is the navigation
+    // there — the other four tabs draw no back arrow, and LocalQuestionContent only renders one when
+    // onBack is non-null (C-TODAY-BACK-001). Pass a handler only from non-tab embeddings, if any ever exist.
+    onBack: (() -> Unit)? = null,
     viewModel: DailyQuestionViewModel = hiltViewModel()
 ) {
     val state by viewModel.uiState.collectAsStateWithLifecycle()