fix(home): clear the Home tab dot when the only enabled tab is read

The Home bottom-bar new-items dot was hardcoded to compare HomeFollows lastRead
against the homeNewThreads feed. Each home tab writes to its own
routeForLastRead (HomeFollows, HomeFollowsReplies, HomeFollowsEverything), so a
user who only enabled the Everything tab could never clear the dot — reading
items only advanced HomeFollowsEverything while the dot stayed lit on the
untouched HomeFollows route.

Recompute homeHasNewItems across all three (route, feed) pairs and gate each
arm by its uiSettingsFlow toggle, so the dot reflects the state of whichever
tabs the user has enabled.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/AccountViewModel.kt

@@ -159,6 +159,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
@@ -397,10 +398,13 @@ class AccountViewModel(
             .stateIn(viewModelScope, SharingStarted.WhileSubscribed(30000), false)
 
     @OptIn(ExperimentalCoroutinesApi::class)
-    val homeHasNewItems =
+    private fun tabHasNewItems(
+        route: String,
+        feedContent: StateFlow<FeedState>,
+    ): Flow<Boolean> =
         combineTransform(
-            account.loadLastReadFlow("HomeFollows"),
-            feedStates.homeNewThreads.feedContent
+            account.loadLastReadFlow(route),
+            feedContent
                 .flatMapLatest {
                     if (it is FeedState.Loaded) {
                         it.feed
@@ -412,15 +416,31 @@ class AccountViewModel(
                 },
         ) { lastRead, newestItemCreatedAt ->
             emit(newestItemCreatedAt != null && newestItemCreatedAt > lastRead)
-        }.onStart {
-            val lastRead = account.loadLastReadFlow("HomeFollows").value
-            val feed = feedStates.homeNewThreads.feedContent.value
-            if (feed is FeedState.Loaded) {
-                val newestItemCreatedAt =
-                    feed.feed.value.list
-                        .firstOrNull { it.event != null && it.event !is GenericRepostEvent && it.event !is RepostEvent }
-                        ?.createdAt()
-                emit(newestItemCreatedAt != null && newestItemCreatedAt > lastRead)
+        }
+
+    val homeHasNewItems: Flow<Boolean> =
+        combine(
+            settings.uiSettingsFlow.showHomeNewThreadsTab,
+            settings.uiSettingsFlow.showHomeConversationsTab,
+            settings.uiSettingsFlow.showHomeEverythingTab,
+            tabHasNewItems("HomeFollows", feedStates.homeNewThreads.feedContent),
+            tabHasNewItems("HomeFollowsReplies", feedStates.homeReplies.feedContent),
+            tabHasNewItems("HomeFollowsEverything", feedStates.homeEverything.feedContent),
+        ) { values ->
+            val showThreads = values[0]
+            val showReplies = values[1]
+            val showEverything = values[2]
+            val threadsHas = values[3]
+            val repliesHas = values[4]
+            val everythingHas = values[5]
+            val anyEnabled = showThreads || showReplies || showEverything
+            if (!anyEnabled) {
+                // HomeScreen falls back to the New Threads tab when the user disables every tab.
+                threadsHas
+            } else {
+                (showThreads && threadsHas) ||
+                    (showReplies && repliesHas) ||
+                    (showEverything && everythingHas)
             }
         }