feat(concord): show the community pill on Concord notifications

Extract the Messages row's highlighted community chip into a shared
ConcordCommunityPill (secondaryContainer, group icon, 20-char cap) and render it
in NoteCompose's header markers for any Concord-gathered note, so a Concord
message surfaced in Notifications names its community and taps through to the
channel list — the same chip, wherever the message appears.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CzJ2Cwo8tg4oZq43oRa3ig

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

@@ -58,6 +58,7 @@ import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
 import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+import com.vitorpamplona.amethyst.commons.model.concord.ConcordChannel
 import com.vitorpamplona.amethyst.commons.model.nip28PublicChats.PublicChatChannel
 import com.vitorpamplona.amethyst.commons.ui.components.GenericLoadable
 import com.vitorpamplona.amethyst.commons.ui.note.HeaderPill
@@ -75,6 +76,7 @@ import com.vitorpamplona.amethyst.ui.components.RobohashFallbackAsyncImage
 import com.vitorpamplona.amethyst.ui.layouts.GenericRepostLayout
 import com.vitorpamplona.amethyst.ui.layouts.NoteComposeLayout
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
+import com.vitorpamplona.amethyst.ui.navigation.routes.Route
 import com.vitorpamplona.amethyst.ui.navigation.routes.routeEditDraftTo
 import com.vitorpamplona.amethyst.ui.navigation.routes.routeFor
 import com.vitorpamplona.amethyst.ui.note.creators.zapsplits.DisplayZapSplits
@@ -200,6 +202,7 @@ import com.vitorpamplona.amethyst.ui.note.types.VideoDisplay
 import com.vitorpamplona.amethyst.ui.note.types.observeZapSender
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.feed.types.RenderChatClip
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord.ConcordCommunityPill
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.nip28PublicChat.RenderPublicChatChannelHeader
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.podcasts.PodcastTrailerListItem
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.workouts.ExerciseTemplateDisplay
@@ -1907,6 +1910,16 @@ fun FirstUserInfoRow(
             PrivateRumorMark(accountViewModel)
         }
 
+        // A Concord message (e.g. surfaced in Notifications) names its parent community with the same
+        // highlighted chip the Messages row uses, tapping through to that community's channel list.
+        val concordChannel = remember(baseNote) { baseNote.inGatherers?.firstNotNullOfOrNull { it as? ConcordChannel } }
+        concordChannel?.communityName?.let { communityName ->
+            ConcordCommunityPill(
+                communityName = communityName,
+                onClick = { nav.nav(Route.ConcordServer(concordChannel.channelId.communityId)) },
+            )
+        }
+
         if (isPinned) {
             PinnedMark()
         }

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

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.icons.symbols.Icon
+import com.vitorpamplona.amethyst.commons.icons.symbols.MaterialSymbols
+
+/**
+ * A tappable chip naming the Concord community a message belongs to. Unlike the muted note-header
+ * markers (PoW/OTS/location), this is a first-class navigation entry point, so it keeps a strong
+ * `secondaryContainer` highlight. Shared by the Messages row and the Notifications feed so a Concord
+ * message reads the same wherever it surfaces. The name is hard-capped so a long title can't crowd
+ * the row.
+ */
+@Composable
+fun ConcordCommunityPill(
+    communityName: String,
+    onClick: () -> Unit,
+    maxChars: Int = 20,
+) {
+    Surface(
+        shape = RoundedCornerShape(6.dp),
+        color = MaterialTheme.colorScheme.secondaryContainer,
+        modifier = Modifier.clickable(onClick = onClick),
+    ) {
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.spacedBy(3.dp),
+            modifier = Modifier.padding(horizontal = 6.dp, vertical = 2.dp),
+        ) {
+            Icon(
+                symbol = MaterialSymbols.Group,
+                contentDescription = null,
+                tint = MaterialTheme.colorScheme.onSecondaryContainer,
+                modifier = Modifier.size(11.dp),
+            )
+            Text(
+                text = if (communityName.length > maxChars) communityName.take(maxChars).trimEnd() + "…" else communityName,
+                style = MaterialTheme.typography.labelSmall,
+                color = MaterialTheme.colorScheme.onSecondaryContainer,
+                maxLines = 1,
+                overflow = TextOverflow.Ellipsis,
+            )
+        }
+    }
+}

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/rooms/ChatroomHeaderCompose.kt

@@ -85,6 +85,7 @@ import com.vitorpamplona.amethyst.ui.note.elements.ToggleableTimeAgoText
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.AccountViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.marmotGroup.marmotGroupLastReadRoute
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.privateDM.header.RoomNameDisplay
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord.ConcordCommunityPill
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.concord.rememberConcordImageModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.publicChannels.ephemChat.LoadEphemeralChatChannel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.rooms.dal.ConcordServerRoomNote
@@ -461,10 +462,9 @@ private fun ConcordRoomCompose(
                 channel.communityName?.let { communityName ->
                     Spacer(Modifier.width(6.dp))
                     // The chip names the parent community and, when tapped, opens that community's
-                    // channel list — the "chip that opens the Concord Channel" entry point. Cap the
-                    // name so a long community title can't crowd out the channel name on the row.
-                    RelayNameChip(
-                        label = communityName.ellipsize(20),
+                    // channel list — the "chip that opens the Concord Channel" entry point.
+                    ConcordCommunityPill(
+                        communityName = communityName,
                         onClick = { nav.nav(Route.ConcordServer(channel.channelId.communityId)) },
                     )
                 }
@@ -604,9 +604,6 @@ private fun RelayNameChip(
     }
 }
 
-/** Hard-caps [this] to [max] characters, appending an ellipsis when it was longer. */
-private fun String.ellipsize(max: Int): String = if (length > max) take(max).trimEnd() + "…" else this
-
 @Composable
 private fun ChannelTitleWithLabelInfo(
     channelName: String,