perf: fix Compose recomposition and flow-leak hot spots

- CardFeedView: use derivedStateOf for isHighlighted so only the
  affected item recomposes on highlight change, not all visible cards;
  switch contentType from javaClass.simpleName (reflection) to item::class
- HomeScreen live-bubbles LazyRow: replace hashCode() key with stable
  channel-id strings and add contentType for proper slot recycling
- UserProfilePicture: wrap room.users.toList() in remember(room) to
  avoid a list allocation every recomposition
- ThreadFeedView / SoftwareAppDetailScreen: remember(item) the
  levelFlowForItem flow so it isn't recreated on every recompose
- ShowDonationCard: remember the observeDonatedInThisVersion() StateFlow
  to prevent a new Eagerly coroutine being started on every recompose

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/note/UserProfilePicture.kt

@@ -232,7 +232,8 @@ fun NonClickableUserPictures(
     size: Dp,
     accountViewModel: AccountViewModel,
 ) {
-    NonClickableUserPictures(room.users.toList(), size, accountViewModel)
+    val userList = remember(room) { room.users.toList() }
+    NonClickableUserPictures(userList, size, accountViewModel)
 }
 
 @Composable

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

@@ -476,7 +476,16 @@ fun DisplayLiveBubbles(
     val feed by liveFeed.feed.collectAsStateWithLifecycle()
 
     LazyRow(HorzPadding, horizontalArrangement = spacedBy(Size5dp)) {
-        itemsIndexed(feed.list, key = { _, item -> item.hashCode() }) { _, item ->
+        itemsIndexed(
+            feed.list,
+            key = { _, item ->
+                when (item) {
+                    is EphemeralChatChannel -> item.roomId.id
+                    is LiveActivitiesChannel -> item.address.toValue()
+                }
+            },
+            contentType = { _, item -> item::class },
+        ) { _, item ->
             when (item) {
                 is EphemeralChatChannel -> RenderEphemeralBubble(item, accountViewModel, nav)
                 is LiveActivitiesChannel -> RenderLiveActivityBubble(item, accountViewModel, nav)

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

@@ -44,6 +44,7 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -232,9 +233,9 @@ private fun FeedLoaded(
         itemsIndexed(
             items = items.list,
             key = { _, item -> item.id() },
-            contentType = { _, item -> item.javaClass.simpleName },
+            contentType = { _, item -> item::class },
         ) { _, item ->
-            val isHighlighted = highlightedCardId == item.id()
+            val isHighlighted by remember(item) { derivedStateOf { highlightedCardId == item.id() } }
             val highlightColor by animateColorAsState(
                 targetValue = if (isHighlighted) MaterialTheme.colorScheme.primaryContainer.copy(alpha = 0.3f) else Color.Transparent,
                 animationSpec = tween(durationMillis = if (isHighlighted) 300 else 1000),

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/notifications/donations/ShowDonationCard.kt

@@ -22,6 +22,7 @@ package com.vitorpamplona.amethyst.ui.screen.loggedIn.notifications.donations
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.BuildConfig
 import com.vitorpamplona.amethyst.ui.components.LoadNote
@@ -34,7 +35,7 @@ fun ShowDonationCard(
     nav: INav,
 ) {
     if (!accountViewModel.account.hasDonatedInThisVersion()) {
-        val donated by accountViewModel.account.observeDonatedInThisVersion().collectAsStateWithLifecycle()
+        val donated by remember { accountViewModel.account.observeDonatedInThisVersion() }.collectAsStateWithLifecycle()
         if (!donated) {
             LoadNote(
                 BuildConfig.RELEASE_NOTES_ID,

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

@@ -331,7 +331,7 @@ private fun SoftwareAppDetailBody(
             key = { _, item -> item.idHex },
             contentType = { _, _ -> "comment" },
         ) { _, item ->
-            val level = threadViewModel.levelFlowForItem(item).collectAsStateWithLifecycle(0)
+            val level = remember(item) { threadViewModel.levelFlowForItem(item) }.collectAsStateWithLifecycle(0)
 
             NoteCompose(
                 baseNote = item,

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

@@ -456,7 +456,7 @@ fun RenderThreadFeed(
                 }
             },
         ) { index, item ->
-            val level = viewModel.levelFlowForItem(item).collectAsStateWithLifecycle(0)
+            val level = remember(item) { viewModel.levelFlowForItem(item) }.collectAsStateWithLifecycle(0)
 
             val modifier =
                 Modifier