feat: make bottom navigation bar per-account via NIP-78

The bottom nav row configuration was an app-global setting stored in the
shared DataStore, so every account shared one bar. Move it into the
per-user NIP-78 app-specific data event (AppSpecificDataEvent) so each
account keeps its own bar and it syncs across the user's devices.

- Add `navigation.bottomBarItems` to AccountSyncedSettingsInternal (the
  serialized/encrypted synced-settings blob) and mirror it as a StateFlow
  in AccountSyncedSettings (seed / toInternal / updateFrom).
- Add AccountSettings.changeBottomBarItems, Account.changeBottomBarItems
  (republishes the NIP-78 event), and AccountViewModel.changeBottomBarItems
  / bottomBarItemsFlow().
- Remove bottomBarItems from the app-global UiSettings / UiSettingsFlow /
  UiSharedPreferences (including the now-unused encode/decode migration
  helpers).
- Point the live bar, navigation rail, preloaders, subscriptions and the
  Bottom Bar settings screen at the per-account flow.

No migration from the previous app-global setting: accounts start from the
default bar, matching the requested behavior.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MJiPHArXZ7P5EvZa7GN9fP

amethyst/src/main/java/com/vitorpamplona/amethyst/model/Account.kt

@@ -160,6 +160,7 @@ import com.vitorpamplona.amethyst.service.relayClient.notifyCommand.model.Notify
 import com.vitorpamplona.amethyst.service.relayClient.reqCommand.nwc.NWCPaymentFilterAssembler
 import com.vitorpamplona.amethyst.service.uploads.FileHeader
 import com.vitorpamplona.amethyst.ui.actions.NewMessageTagger
+import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.EventProcessor
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord.concordChannelLastReadRoute
 import com.vitorpamplona.quartz.buzz.dm.DmAddMemberEvent
@@ -1024,6 +1025,12 @@ class Account(
         }
     }
 
+    suspend fun changeBottomBarItems(items: List<BottomBarEntry>) {
+        if (settings.changeBottomBarItems(items)) {
+            sendNewAppSpecificData()
+        }
+    }
+
     suspend fun toggleChatroomPin(room: ChatroomKey) {
         settings.toggleChatroomPin(room)
         sendNewAppSpecificData()

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSettings.kt

@@ -38,6 +38,7 @@ import com.vitorpamplona.amethyst.commons.service.pow.PoWCategory
 import com.vitorpamplona.amethyst.model.nip60Cashu.CashuPreferences
 import com.vitorpamplona.amethyst.ui.actions.mediaServers.DEFAULT_MEDIA_SERVERS
 import com.vitorpamplona.amethyst.ui.actions.mediaServers.ServerName
+import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
 import com.vitorpamplona.amethyst.ui.screen.FeedDefinition
 import com.vitorpamplona.quartz.concord.cord02Community.ConcordCommunityListEvent
 import com.vitorpamplona.quartz.experimental.ephemChat.list.EphemeralChatListEvent
@@ -473,6 +474,15 @@ class AccountSettings(
         return false
     }
 
+    fun changeBottomBarItems(newItems: List<BottomBarEntry>): Boolean {
+        if (syncedSettings.navigation.bottomBarItems.value != newItems) {
+            syncedSettings.navigation.bottomBarItems.tryEmit(newItems)
+            saveAccountSettings()
+            return true
+        }
+        return false
+    }
+
     /** The selected default spend rail across both NWC wallets and CLINK debits. */
     fun defaultPaymentSource(): PaymentSource? = PaymentSourceResolver.resolveDefault(nwcWallets.value, clinkDebitWallets.value, defaultPaymentSourceId.value)
 

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSyncedSettings.kt

@@ -24,6 +24,7 @@ import androidx.compose.runtime.Stable
 import com.vitorpamplona.amethyst.commons.audio.VisualizerStyle
 import com.vitorpamplona.amethyst.commons.service.pow.PoWCategory
 import com.vitorpamplona.amethyst.commons.service.pow.PoWPolicy
+import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.notifications.equalImmutableLists
 import com.vitorpamplona.quartz.nip17Dm.base.ChatroomKey
 import com.vitorpamplona.quartz.nip57Zaps.LnZapEvent
@@ -79,6 +80,10 @@ class AccountSyncedSettings(
             MutableStateFlow(internalSettings.proofOfWork.difficulty),
             MutableStateFlow(PoWCategory.fromIds(internalSettings.proofOfWork.enabledCategories)),
         )
+    val navigation =
+        AccountNavigationPreferences(
+            MutableStateFlow(internalSettings.navigation.bottomBarItems),
+        )
 
     fun toInternal(): AccountSyncedSettingsInternal =
         AccountSyncedSettingsInternal(
@@ -119,6 +124,7 @@ class AccountSyncedSettings(
                         .map { it.id }
                         .sorted(),
                 ),
+            navigation = AccountNavigationPreferencesInternal(navigation.bottomBarItems.value),
         )
 
     fun updateFrom(syncedSettingsInternal: AccountSyncedSettingsInternal) {
@@ -210,6 +216,11 @@ class AccountSyncedSettings(
         if (proofOfWork.enabledCategories.value != newPoWCategories) {
             proofOfWork.enabledCategories.tryEmit(newPoWCategories)
         }
+
+        val newBottomBarItems = syncedSettingsInternal.navigation.bottomBarItems
+        if (navigation.bottomBarItems.value != newBottomBarItems) {
+            navigation.bottomBarItems.tryEmit(newBottomBarItems)
+        }
     }
 
     fun dontTranslateFromFilteredBySpokenLanguages(): Set<String> = languages.dontTranslateFrom.value - getLanguagesSpokenByUser()
@@ -308,6 +319,11 @@ class AccountMediaPreferences(
     val audioVisualizer: MutableStateFlow<VisualizerStyle>,
 )
 
+@Stable
+class AccountNavigationPreferences(
+    val bottomBarItems: MutableStateFlow<List<BottomBarEntry>>,
+)
+
 @Stable
 class AccountChatPreferences(
     val pinnedChatrooms: MutableStateFlow<Set<ChatroomKey>>,

amethyst/src/main/java/com/vitorpamplona/amethyst/model/AccountSyncedSettingsInternal.kt

@@ -23,6 +23,8 @@ package com.vitorpamplona.amethyst.model
 import android.content.res.Resources
 import androidx.core.os.ConfigurationCompat
 import com.vitorpamplona.amethyst.commons.service.pow.PoWCategory
+import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
+import com.vitorpamplona.amethyst.ui.navigation.bottombars.DefaultBottomBarEntries
 import com.vitorpamplona.quartz.nip57Zaps.LnZapEvent
 import kotlinx.serialization.Serializable
 import java.util.Locale
@@ -159,6 +161,15 @@ class AccountSyncedSettingsInternal(
     val media: AccountMediaPreferencesInternal = AccountMediaPreferencesInternal(),
     val chats: AccountChatPreferencesInternal = AccountChatPreferencesInternal(),
     val proofOfWork: AccountPoWPreferencesInternal = AccountPoWPreferencesInternal(),
+    val navigation: AccountNavigationPreferencesInternal = AccountNavigationPreferencesInternal(),
+)
+
+@Serializable
+class AccountNavigationPreferencesInternal(
+    // The ordered list of tabs pinned to the bottom navigation bar (built-ins,
+    // favorite apps, and individual joined chats/groups). Defaulted so blobs
+    // written before this field existed decode to the app's current defaults.
+    var bottomBarItems: List<BottomBarEntry> = DefaultBottomBarEntries,
 )
 
 @Serializable

amethyst/src/main/java/com/vitorpamplona/amethyst/model/UiSettings.kt

@@ -22,8 +22,6 @@ package com.vitorpamplona.amethyst.model
 
 import androidx.compose.runtime.Stable
 import com.vitorpamplona.amethyst.R
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.DefaultBottomBarEntries
 import kotlinx.serialization.Serializable
 
 @Stable
@@ -44,7 +42,6 @@ data class UiSettings(
     val automaticallyProposeAiImprovements: BooleanType = BooleanType.ALWAYS,
     val useTrackedBroadcasts: BooleanType = BooleanType.ALWAYS,
     val automaticallyCreateDrafts: BooleanType = BooleanType.ALWAYS,
-    val bottomBarItems: List<BottomBarEntry> = DefaultBottomBarEntries,
     val showHomeNewThreadsTab: Boolean = true,
     val showHomeConversationsTab: Boolean = true,
     val showHomeEverythingTab: Boolean = false,

amethyst/src/main/java/com/vitorpamplona/amethyst/model/UiSettingsFlow.kt

@@ -21,8 +21,6 @@
 package com.vitorpamplona.amethyst.model
 
 import androidx.compose.runtime.Stable
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.DefaultBottomBarEntries
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
@@ -44,7 +42,6 @@ class UiSettingsFlow(
     val automaticallyProposeAiImprovements: MutableStateFlow<BooleanType> = MutableStateFlow(BooleanType.ALWAYS),
     val useTrackedBroadcasts: MutableStateFlow<BooleanType> = MutableStateFlow(BooleanType.ALWAYS),
     val automaticallyCreateDrafts: MutableStateFlow<BooleanType> = MutableStateFlow(BooleanType.ALWAYS),
-    val bottomBarItems: MutableStateFlow<List<BottomBarEntry>> = MutableStateFlow(DefaultBottomBarEntries),
     val showHomeNewThreadsTab: MutableStateFlow<Boolean> = MutableStateFlow(true),
     val showHomeConversationsTab: MutableStateFlow<Boolean> = MutableStateFlow(true),
     val showHomeEverythingTab: MutableStateFlow<Boolean> = MutableStateFlow(false),
@@ -77,7 +74,6 @@ class UiSettingsFlow(
             automaticallyProposeAiImprovements,
             useTrackedBroadcasts,
             automaticallyCreateDrafts,
-            bottomBarItems,
             showHomeNewThreadsTab,
             showHomeConversationsTab,
             showHomeEverythingTab,
@@ -114,7 +110,7 @@ class UiSettingsFlow(
                 flows[12] as BooleanType,
                 flows[13] as BooleanType,
                 flows[14] as BooleanType,
-                flows[15] as List<BottomBarEntry>,
+                flows[15] as Boolean,
                 flows[16] as Boolean,
                 flows[17] as Boolean,
                 flows[18] as Boolean,
@@ -122,13 +118,12 @@ class UiSettingsFlow(
                 flows[20] as Boolean,
                 flows[21] as Boolean,
                 flows[22] as Boolean,
-                flows[23] as Boolean,
-                flows[24] as BooleanType,
-                flows[25] as AccentColorType,
-                flows[26] as FontFamilyType,
-                flows[27] as FontSizeType,
-                flows[28] as String,
-                flows[29] as Boolean,
+                flows[23] as BooleanType,
+                flows[24] as AccentColorType,
+                flows[25] as FontFamilyType,
+                flows[26] as FontSizeType,
+                flows[27] as String,
+                flows[28] as Boolean,
             )
         }
 
@@ -149,7 +144,6 @@ class UiSettingsFlow(
             automaticallyProposeAiImprovements.value,
             useTrackedBroadcasts.value,
             automaticallyCreateDrafts.value,
-            bottomBarItems.value,
             showHomeNewThreadsTab.value,
             showHomeConversationsTab.value,
             showHomeEverythingTab.value,
@@ -229,10 +223,6 @@ class UiSettingsFlow(
             automaticallyCreateDrafts.tryEmit(torSettings.automaticallyCreateDrafts)
             any = true
         }
-        if (bottomBarItems.value != torSettings.bottomBarItems) {
-            bottomBarItems.tryEmit(torSettings.bottomBarItems)
-            any = true
-        }
         if (showHomeNewThreadsTab.value != torSettings.showHomeNewThreadsTab) {
             showHomeNewThreadsTab.tryEmit(torSettings.showHomeNewThreadsTab)
             any = true
@@ -329,7 +319,6 @@ class UiSettingsFlow(
                 MutableStateFlow(uiSettings.automaticallyProposeAiImprovements),
                 MutableStateFlow(uiSettings.useTrackedBroadcasts),
                 MutableStateFlow(uiSettings.automaticallyCreateDrafts),
-                MutableStateFlow(uiSettings.bottomBarItems),
                 MutableStateFlow(uiSettings.showHomeNewThreadsTab),
                 MutableStateFlow(uiSettings.showHomeConversationsTab),
                 MutableStateFlow(uiSettings.showHomeEverythingTab),

amethyst/src/main/java/com/vitorpamplona/amethyst/model/preferences/UISharedPreferences.kt

@@ -41,10 +41,6 @@ import com.vitorpamplona.amethyst.model.ProfileGalleryType
 import com.vitorpamplona.amethyst.model.ThemeType
 import com.vitorpamplona.amethyst.model.UiSettings
 import com.vitorpamplona.amethyst.model.UiSettingsFlow
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.DefaultBottomBarEntries
-import com.vitorpamplona.amethyst.ui.navigation.bottombars.NavBarItem
-import com.vitorpamplona.quartz.nip01Core.core.JsonMapper
 import com.vitorpamplona.quartz.utils.Log
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
@@ -113,7 +109,6 @@ class UiSharedPreferences(
         val UI_PROPOSE_AI_IMPROVEMENTS = stringPreferencesKey("ui.propose_ai_improvements")
         val UI_USE_TRACKED_BROADCASTS = stringPreferencesKey("ui.use_tracked_broadcasts")
         val UI_AUTOMATICALLY_CREATE_DRAFTS = stringPreferencesKey("ui.automatically_create_drafts")
-        val UI_BOTTOM_BAR_ITEMS = stringPreferencesKey("ui.bottom_bar_items")
         val UI_SHOW_HOME_NEW_THREADS_TAB = booleanPreferencesKey("ui.show_home_new_threads_tab")
         val UI_SHOW_HOME_CONVERSATIONS_TAB = booleanPreferencesKey("ui.show_home_conversations_tab")
         val UI_SHOW_HOME_EVERYTHING_TAB = booleanPreferencesKey("ui.show_home_everything_tab")
@@ -154,7 +149,6 @@ class UiSharedPreferences(
                         preferences[UI_USE_TRACKED_BROADCASTS]?.let { BooleanType.valueOf(it) }
                             ?: if (featureSet == FeatureSetType.COMPLETE) BooleanType.ALWAYS else BooleanType.NEVER,
                     automaticallyCreateDrafts = preferences[UI_AUTOMATICALLY_CREATE_DRAFTS]?.let { BooleanType.valueOf(it) } ?: BooleanType.ALWAYS,
-                    bottomBarItems = preferences[UI_BOTTOM_BAR_ITEMS]?.let { decodeBottomBarItems(it) } ?: DefaultBottomBarEntries,
                     showHomeNewThreadsTab = preferences[UI_SHOW_HOME_NEW_THREADS_TAB] ?: true,
                     showHomeConversationsTab = preferences[UI_SHOW_HOME_CONVERSATIONS_TAB] ?: true,
                     showHomeEverythingTab = preferences[UI_SHOW_HOME_EVERYTHING_TAB] ?: false,
@@ -209,7 +203,6 @@ class UiSharedPreferences(
                     preferences[UI_PROPOSE_AI_IMPROVEMENTS] = sharedSettings.automaticallyProposeAiImprovements.name
                     preferences[UI_USE_TRACKED_BROADCASTS] = sharedSettings.useTrackedBroadcasts.name
                     preferences[UI_AUTOMATICALLY_CREATE_DRAFTS] = sharedSettings.automaticallyCreateDrafts.name
-                    preferences[UI_BOTTOM_BAR_ITEMS] = encodeBottomBarItems(sharedSettings.bottomBarItems)
                     preferences[UI_SHOW_HOME_NEW_THREADS_TAB] = sharedSettings.showHomeNewThreadsTab
                     preferences[UI_SHOW_HOME_CONVERSATIONS_TAB] = sharedSettings.showHomeConversationsTab
                     preferences[UI_SHOW_HOME_EVERYTHING_TAB] = sharedSettings.showHomeEverythingTab
@@ -231,42 +224,5 @@ class UiSharedPreferences(
                 Log.e("SharedPreferences") { "Error saving DataStore preferences: ${e.message}" }
             }
         }
-
-        /**
-         * Persists "follow the defaults" as a blank sentinel instead of the concrete default list.
-         *
-         * A user who resets the bottom bar (or who never customized it) should track whatever
-         * [DefaultBottomBarEntries] is in the *installed* app version. Storing the concrete list would
-         * pin them to today's default, so a future version that changes the default would never reach
-         * them. Storing a blank value instead makes [decodeBottomBarItems] resolve it back to the
-         * current [DefaultBottomBarEntries] on every load — i.e. the user is automatically migrated to
-         * the new default. Any genuinely customized bar is still stored as JSON.
-         */
-        internal fun encodeBottomBarItems(items: List<BottomBarEntry>): String = if (items == DefaultBottomBarEntries) "" else JsonMapper.toJson(items)
-
-        internal fun decodeBottomBarItems(raw: String): List<BottomBarEntry>? {
-            if (raw.isBlank()) return DefaultBottomBarEntries
-            // Current format: a JSON list of BottomBarEntry (built-ins + favorites).
-            runCatching { return JsonMapper.fromJson<List<BottomBarEntry>>(raw) }
-            // Configs written before the stable @SerialName discriminators used the fully-qualified
-            // class name as the polymorphic "type" value. Rewrite it to the short name and retry, so a
-            // customized bar survives the upgrade instead of silently resetting to defaults.
-            runCatching {
-                val migrated =
-                    raw
-                        .replace(LEGACY_BUILTIN_DISCRIMINATOR, "builtIn")
-                        .replace(LEGACY_FAVORITE_DISCRIMINATOR, "favorite")
-                return JsonMapper.fromJson<List<BottomBarEntry>>(migrated)
-            }
-            // Oldest format: comma-joined NavBarItem enum names (before favorites/unified entries).
-            val legacy = raw.split(",").mapNotNull { name -> runCatching { NavBarItem.valueOf(name) }.getOrNull() }
-            if (legacy.isNotEmpty()) return legacy.map { BottomBarEntry.BuiltIn(it) }
-            // Unrecognizable — fall back to the defaults rather than leaving the bar empty.
-            return DefaultBottomBarEntries
-        }
-
-        // The pre-@SerialName polymorphic discriminators (fully-qualified class names) for migration.
-        private const val LEGACY_BUILTIN_DISCRIMINATOR = "com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry.BuiltIn"
-        private const val LEGACY_FAVORITE_DISCRIMINATOR = "com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry.Favorite"
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/AppNavigation.kt

@@ -348,7 +348,7 @@ fun AppNavigation(
                 // holding their surfaces attached. Below the drawer (drawn by the layout above) and below
                 // dialogs (separate windows). API 30+ only, matching the embedded-surface feature.
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
-                    val bottomBarItems by accountViewModel.settings.uiSettingsFlow.bottomBarItems
+                    val bottomBarItems by accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
                         .collectAsStateWithLifecycle()
                     // Move every embedded app to the new account on a switch. Mounted before the layer and
                     // the preloader so the previous account's sessions are dropped ahead of the first sweep

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/AppBottomBar.kt

@@ -95,7 +95,7 @@ fun AppBottomBar(
     // pushes). Mirrors the back-arrow rule in canPop().
     if (nav.canPop()) return
 
-    val items by accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val items by accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
         .collectAsStateWithLifecycle()
     if (items.isEmpty()) {
         Spacer(

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/AppNavigationRail.kt

@@ -55,7 +55,7 @@ fun AppNavigationRail(
     nav: Nav,
     accountViewModel: AccountViewModel,
 ) {
-    val items by accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val items by accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
         .collectAsStateWithLifecycle()
     val favorites by FavoriteAppsRegistry.favorites.collectAsStateWithLifecycle()
     val favoritesById = remember(favorites) { favorites.associateBy { it.id } }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/BottomBarEntry.kt

@@ -24,10 +24,11 @@ import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 /**
- * One slot in the bottom navigation bar. A single ordered list of these (persisted in
- * [com.vitorpamplona.amethyst.model.UiSettings.bottomBarItems]) holds built-in destinations,
- * favorite apps, and individual joined chats/groups, so the user can pin and drag-reorder them
- * together in one list.
+ * One slot in the bottom navigation bar. A single ordered list of these (persisted per-account in
+ * the NIP-78 app-specific data event via
+ * [com.vitorpamplona.amethyst.model.AccountNavigationPreferencesInternal.bottomBarItems]) holds
+ * built-in destinations, favorite apps, and individual joined chats/groups, so the user can pin and
+ * drag-reorder them together in one list.
  *
  * - [BuiltIn] resolves its [Route][com.vitorpamplona.amethyst.ui.navigation.routes.Route] (and its
  *   icon/label/notification badge) through [NavBarCatalog], like before.

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

@@ -675,7 +675,7 @@ class AccountViewModel(
     fun importConcordCommunities() =
         viewModelScope.launch(Dispatchers.IO) {
             val pinnedRelays =
-                settings.uiSettingsFlow.bottomBarItems.value
+                account.settings.syncedSettings.navigation.bottomBarItems.value
                     .flatMap {
                         when (it) {
                             is BottomBarEntry.Concord -> it.relays
@@ -1935,6 +1935,13 @@ class AccountViewModel(
             account.changeAudioVisualizer(style)
         }
 
+    fun bottomBarItemsFlow(): StateFlow<List<BottomBarEntry>> = account.settings.syncedSettings.navigation.bottomBarItems
+
+    fun changeBottomBarItems(items: List<BottomBarEntry>) =
+        launchSigner {
+            account.changeBottomBarItems(items)
+        }
+
     fun pinnedChatroomsFlow(): StateFlow<Set<ChatroomKey>> = account.settings.syncedSettings.chats.pinnedChatrooms
 
     fun toggleChatroomPin(room: ChatroomKey) =

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

@@ -64,7 +64,7 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.workouts.datasource.Workout
  */
 @Composable
 fun BottomBarFeedPreloaders(accountViewModel: AccountViewModel) {
-    val items by accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val items by accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
         .collectAsStateWithLifecycle()
 
     // Only built-in destinations have feeds to preload; favorite-app entries embed their own content.

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

@@ -163,7 +163,7 @@ private fun EmbeddedWebAppTab(
     // SideEffect so it runs after [setActive]; the host short-circuits the identical remembered instance.
     SideEffect { EmbeddedTabHost.setActiveChrome(id, chrome) }
 
-    val bottomBarFlow = accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val bottomBarFlow = accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
     DisposableEffect(id) {
         val token = EmbeddedTabHost.setActive(id)
         onDispose {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/concord/datasource/ConcordChannelSubscription.kt

@@ -194,7 +194,7 @@ private const val RECONNECT_RESWEEP_MIN_INTERVAL_MS = 60_000L
 @Composable
 private fun bootstrapPinnedCommunities(accountViewModel: AccountViewModel) {
     val account = accountViewModel.account
-    val items by accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val items by accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
         .collectAsStateWithLifecycle()
     val communities by account.concordChannelList.liveCommunities.collectAsStateWithLifecycle()
 

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

@@ -53,7 +53,7 @@ fun EmbeddedTabPreloader(accountViewModel: AccountViewModel) {
     val context = LocalContext.current
     val backgroundColor = MaterialTheme.colorScheme.background.toArgb()
 
-    val bottomBarItems by accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val bottomBarItems by accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
         .collectAsStateWithLifecycle()
     val favoriteIds = bottomBarItems.favoriteIds()
 

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

@@ -175,7 +175,7 @@ private fun EmbeddedNostrAppTab(
     // so it runs after [setActive]; the host short-circuits the identical remembered instance.
     SideEffect { EmbeddedTabHost.setActiveChrome(id, chrome) }
 
-    val bottomBarFlow = accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    val bottomBarFlow = accountViewModel.account.settings.syncedSettings.navigation.bottomBarItems
     DisposableEffect(id) {
         val token = EmbeddedTabHost.setActive(id)
         onDispose {

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

@@ -150,12 +150,14 @@ fun BottomBarSettingsScreen(
 
 @Composable
 fun BottomBarSettingsContent(accountViewModel: AccountViewModel) {
-    val bottomBarItemsFlow = accountViewModel.settings.uiSettingsFlow.bottomBarItems
+    // Per-account bottom bar, synced through the NIP-78 app-specific data event.
+    val bottomBarItemsFlow = accountViewModel.bottomBarItemsFlow()
     val savedItems by bottomBarItemsFlow.collectAsStateWithLifecycle()
 
     // All pin/unpin/reorder logic lives in the holder (unit-tested); the composable only renders and
-    // forwards events. syncFrom re-seeds when the saved list changes elsewhere without clobbering a drag.
-    val state = remember { BottomBarSettingsState(savedItems) { bottomBarItemsFlow.tryEmit(it) } }
+    // forwards events. Each persist republishes the account's NIP-78 settings event. syncFrom re-seeds
+    // when the saved list changes elsewhere without clobbering a drag.
+    val state = remember { BottomBarSettingsState(savedItems) { accountViewModel.changeBottomBarItems(it) } }
     LaunchedEffect(savedItems) { state.syncFrom(savedItems) }
 
     val pinned = state.pinned

amethyst/src/test/java/com/vitorpamplona/amethyst/model/preferences/BottomBarPersistenceTest.kt

@@ -20,42 +20,44 @@
  */
 package com.vitorpamplona.amethyst.model.preferences
 
+import com.vitorpamplona.amethyst.model.AccountNavigationPreferencesInternal
 import com.vitorpamplona.amethyst.ui.navigation.bottombars.BottomBarEntry
 import com.vitorpamplona.amethyst.ui.navigation.bottombars.DefaultBottomBarEntries
 import com.vitorpamplona.amethyst.ui.navigation.bottombars.NavBarItem
+import com.vitorpamplona.quartz.nip01Core.core.JsonMapper
 import org.junit.Assert.assertEquals
 import org.junit.Test
 
 /**
- * Locks the "reset to defaults migrates automatically" behavior.
- *
- * Resetting the bottom bar (or never customizing it) is persisted as a blank sentinel rather than the
- * concrete default list, so that a user on the defaults tracks whatever [DefaultBottomBarEntries] the
- * *installed* app version ships. If a future version changes the default, that blank value resolves to
- * the new default on load — the user is migrated instead of being pinned to the old default.
+ * Locks the per-account bottom-bar persistence: the pinned list now lives inside the NIP-78
+ * app-specific data blob ([AccountNavigationPreferencesInternal], one field of
+ * [com.vitorpamplona.amethyst.model.AccountSyncedSettingsInternal]) rather than the app-global
+ * DataStore, so every account keeps its own bar and it syncs across the user's devices.
  */
 class BottomBarPersistenceTest {
     @Test
-    fun defaultsAreStoredAsBlankSentinel() {
-        assertEquals("", UiSharedPreferences.encodeBottomBarItems(DefaultBottomBarEntries))
+    fun defaultsRoundTripThroughSyncedSettingsBlob() {
+        val decoded = JsonMapper.fromJson<AccountNavigationPreferencesInternal>(JsonMapper.toJson(AccountNavigationPreferencesInternal()))
+        assertEquals(DefaultBottomBarEntries, decoded.bottomBarItems)
     }
 
     @Test
-    fun blankSentinelDecodesToCurrentDefaults() {
-        // The blank sentinel resolves to whatever DefaultBottomBarEntries this build ships. Because it
-        // returns the current constant (not a value frozen at reset time), a future version that changes
-        // the default automatically migrates every user who is on the defaults.
-        assertEquals(DefaultBottomBarEntries, UiSharedPreferences.decodeBottomBarItems(""))
+    fun blobWrittenBeforeTheNavigationFieldExistedDecodesToCurrentDefaults() {
+        // Older clients (and older Amethyst builds) never wrote the `bottomBarItems` field. The default
+        // means such a blob decodes to whatever DefaultBottomBarEntries the installed build ships — no
+        // migration from the old app-global setting is attempted, matching the intended behavior.
+        val decoded = JsonMapper.fromJson<AccountNavigationPreferencesInternal>("{}")
+        assertEquals(DefaultBottomBarEntries, decoded.bottomBarItems)
     }
 
     @Test
-    fun customizedBarIsStoredVerbatimAndRoundTrips() {
+    fun customizedBarRoundTripsThroughSyncedSettingsBlob() {
         val custom =
-            listOf(
+            listOf<BottomBarEntry>(
                 BottomBarEntry.BuiltIn(NavBarItem.HOME),
                 BottomBarEntry.Favorite("url:https://example.com"),
             )
-        val encoded = UiSharedPreferences.encodeBottomBarItems(custom)
-        assertEquals(custom, UiSharedPreferences.decodeBottomBarItems(encoded))
+        val decoded = JsonMapper.fromJson<AccountNavigationPreferencesInternal>(JsonMapper.toJson(AccountNavigationPreferencesInternal(custom)))
+        assertEquals(custom, decoded.bottomBarItems)
     }
 }