fix(nip29): audit fixes for pinned-message jump and back-fill

- Jump effect: key on the note id alone and always clear the request
  after one attempt. Previously keyed on (id, items.list), so a message
  arriving mid-jump cancelled the scroll animation and could leave the
  request stuck (never cleared when the target wasn't loaded), blocking
  repeat taps. Now the animation can't be interrupted and a re-tap always
  re-fires.
- Back-fill pinned bodies: add an id-scoped filter for the group's
  pinnedEventIds on the host relay. A pin can point at a message older
  than the 200-item timeline window, which the h-scoped timeline never
  returns — without this the bar shows a blank preview and can't jump.
- Re-invalidate the relay-group filter when the pin list changes (keyed
  on the pin ids only, so roster/metadata churn doesn't re-subscribe), so
  the new pin ids are actually requested when 39005 arrives.

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/feed/ChatFeedView.kt

@@ -194,18 +194,18 @@ fun ChatFeedLoaded(
         }
     }
 
-    // External jump request (pinned-message bar). Re-runs when the requested id changes or the loaded
-    // list shifts (so a pin that arrives after the tap still scrolls once loaded). Clears the request
-    // as soon as it lands, so a repeat tap on the same pin fires again.
+    // External jump request (pinned-message bar). Keyed on the id alone, so a message arriving mid-jump
+    // can't cancel the scroll animation or restart the effect. Always clears the request after one
+    // attempt — even when the target isn't loaded — so it never sticks and a repeat tap fires again.
     val jumpId = jumpToNoteId?.value
-    LaunchedEffect(jumpId, items.list) {
+    LaunchedEffect(jumpId) {
         if (jumpId != null) {
             val index = items.list.indexOfFirst { it.idHex == jumpId }
             if (index >= 0) {
                 listState.animateScrollToItem(index)
                 highlightedNoteId.value = jumpId
-                onJumpHandled()
             }
+            onJumpHandled()
         }
     }
 

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

@@ -26,6 +26,7 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.commons.model.Channel
+import com.vitorpamplona.amethyst.commons.model.nip29RelayGroups.RelayGroupChannel
 import com.vitorpamplona.amethyst.commons.model.nip53LiveActivities.LiveActivitiesChannel
 import com.vitorpamplona.amethyst.commons.relayClient.subscriptions.LifecycleAwareKeyDataSourceSubscription
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
@@ -58,4 +59,18 @@ fun ChannelFilterAssemblerSubscription(
             dataSource.invalidateFilters()
         }
     }
+
+    // Relay groups: when the kind-39005 pin list changes, re-invalidate so the id-based back-fill
+    // for pinned message bodies (see filterMetadataToRelayGroup) picks up the new ids. Keyed on the
+    // pin list alone, so unrelated roster/metadata churn doesn't force a re-subscribe.
+    if (channel is RelayGroupChannel) {
+        val metadataState by channel
+            .flow()
+            .metadata.stateFlow
+            .collectAsStateWithLifecycle()
+        val pinnedIds = (metadataState.channel as? RelayGroupChannel)?.pinnedEventIds ?: channel.pinnedEventIds
+        LaunchedEffect(pinnedIds) {
+            dataSource.invalidateFilters()
+        }
+    }
 }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/publicChannels/datasource/subassemblies/FilterMetadataToRelayGroup.kt

@@ -49,15 +49,32 @@ private val RELAY_GROUP_METADATA_KINDS =
 fun filterMetadataToRelayGroup(
     channel: RelayGroupChannel,
     since: SincePerRelayMap?,
-): List<RelayBasedFilter> =
-    channel.relays().toSet().map {
-        RelayBasedFilter(
-            relay = it,
-            filter =
-                Filter(
-                    kinds = RELAY_GROUP_METADATA_KINDS,
-                    tags = mapOf("d" to listOf(channel.groupId.id)),
-                    since = since?.get(it)?.time,
-                ),
-        )
-    }
+): List<RelayBasedFilter> {
+    val relays = channel.relays().toSet()
+    val directory =
+        relays.map {
+            RelayBasedFilter(
+                relay = it,
+                filter =
+                    Filter(
+                        kinds = RELAY_GROUP_METADATA_KINDS,
+                        tags = mapOf("d" to listOf(channel.groupId.id)),
+                        since = since?.get(it)?.time,
+                    ),
+            )
+        }
+
+    // Back-fill the bodies of pinned messages by id from the host relay. A pin can point at a
+    // message older than the 200-item timeline window, which the `h`-scoped timeline filter would
+    // never return — without this the pin bar shows a blank preview and can't jump to it. No `since`:
+    // pinned events are immutable, so we want them regardless of age.
+    val pinnedIds = channel.pinnedEventIds
+    val pins =
+        if (pinnedIds.isEmpty()) {
+            emptyList()
+        } else {
+            relays.map { RelayBasedFilter(relay = it, filter = Filter(ids = pinnedIds)) }
+        }
+
+    return directory + pins
+}