refactor: render pinned followed chats as a separate LazyColumn section

Instead of sorting followed chats to the top of the existing feed (which
hides them when the feed filter or TopFilter excludes them), render them
in a dedicated items{} block above the rest of the feed and skip them in
the main itemsIndexed{} block. This keeps the feed filter, feedKey, and
screen watchers untouched.

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

@@ -23,14 +23,19 @@ package com.vitorpamplona.amethyst.ui.screen.loggedIn.publicChats
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyItemScope
 import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.itemsIndexed
 import androidx.compose.material3.HorizontalDivider
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.commons.ui.feeds.FeedState
+import com.vitorpamplona.amethyst.model.LocalCache
+import com.vitorpamplona.amethyst.model.Note
 import com.vitorpamplona.amethyst.ui.layouts.rememberFeedContentPadding
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
@@ -47,30 +52,58 @@ fun PublicChatsFeedLoaded(
     nav: INav,
 ) {
     val items by loaded.feed.collectAsStateWithLifecycle()
+    val followedSet by accountViewModel.account.publicChatList.flowSet
+        .collectAsStateWithLifecycle()
+
+    val pinned =
+        remember(followedSet) {
+            followedSet.mapNotNull { idHex ->
+                LocalCache.getNoteIfExists(idHex)?.takeIf { it.event is ChannelCreateEvent }
+            }
+        }
 
     LazyColumn(
         contentPadding = rememberFeedContentPadding(FeedPadding),
         state = listState,
     ) {
+        items(
+            pinned,
+            key = { item -> "pinned-" + item.idHex },
+            contentType = { item -> item.event?.kind ?: -1 },
+        ) { item ->
+            PublicChatRow(item, accountViewModel, nav)
+        }
+
         itemsIndexed(
             items.list,
             key = { _, item -> item.idHex },
             contentType = { _, item -> item.event?.kind ?: -1 },
         ) { _, item ->
-            Row(Modifier.fillMaxWidth().animateItem()) {
-                ChannelCardCompose(
-                    baseNote = item,
-                    routeForLastRead = "PublicChatsFeed",
-                    modifier = Modifier.fillMaxWidth(),
-                    forceEventKind = ChannelCreateEvent.KIND,
-                    accountViewModel = accountViewModel,
-                    nav = nav,
-                )
+            if (item.idHex !in followedSet) {
+                PublicChatRow(item, accountViewModel, nav)
             }
-
-            HorizontalDivider(
-                thickness = DividerThickness,
-            )
         }
     }
 }
+
+@Composable
+private fun LazyItemScope.PublicChatRow(
+    item: Note,
+    accountViewModel: AccountViewModel,
+    nav: INav,
+) {
+    Row(Modifier.fillMaxWidth().animateItem()) {
+        ChannelCardCompose(
+            baseNote = item,
+            routeForLastRead = "PublicChatsFeed",
+            modifier = Modifier.fillMaxWidth(),
+            forceEventKind = ChannelCreateEvent.KIND,
+            accountViewModel = accountViewModel,
+            nav = nav,
+        )
+    }
+
+    HorizontalDivider(
+        thickness = DividerThickness,
+    )
+}

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

@@ -106,10 +106,8 @@ fun WatchAccountForPublicChatsScreen(
     val hiddenUsers =
         accountViewModel.account.hiddenUsers.flow
             .collectAsStateWithLifecycle()
-    val followedChats by accountViewModel.account.publicChatList.flowSet
-        .collectAsStateWithLifecycle()
 
-    LaunchedEffect(accountViewModel, listState, hiddenUsers, followedChats) {
+    LaunchedEffect(accountViewModel, listState, hiddenUsers) {
         publicChatsFeedState.checkKeysInvalidateDataAndSendToTop()
     }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/publicChats/dal/PublicChatsFeedFilter.kt

@@ -32,10 +32,7 @@ import com.vitorpamplona.quartz.nip28PublicChat.base.IsInPublicChatChannel
 class PublicChatsFeedFilter(
     val account: Account,
 ) : AdditiveFeedFilter<Note>() {
-    override fun feedKey(): String =
-        account.userProfile().pubkeyHex + "-" + followList().code + "-" +
-            account.publicChatList.flowSet.value
-                .hashCode()
+    override fun feedKey(): String = account.userProfile().pubkeyHex + "-" + followList().code
 
     override fun limit() = 200
 
@@ -108,8 +105,6 @@ class PublicChatsFeedFilter(
     }
 
     override fun sort(items: Set<Note>): List<Note> {
-        val followedSet = account.publicChatList.flowSet.value
-
         val lastNote =
             items.associateWith { note ->
                 LocalCache.getPublicChatChannelIfExists(note.idHex)?.lastNote?.createdAt() ?: 0L
@@ -122,8 +117,6 @@ class PublicChatsFeedFilter(
 
         val comparator: Comparator<Note> =
             compareByDescending<Note> {
-                it.idHex in followedSet
-            }.thenByDescending {
                 lastNote[it]
             }.thenByDescending {
                 createdNote[it]