fix(concord): confirm before banning a member

Ban fired straight from the overflow menu while Remove asked first. A ban can
be lifted here, but other clients (Armada) drop the community from a banned
member's list on sight, so a mis-tap still costs them the community. Ask first,
reusing the Remove dialog; unban stays one tap.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

commonsUI/src/commonMain/composeResources/values/strings.xml

@@ -3642,6 +3642,8 @@
         <item quantity="other">%1$d members</item>
     </plurals>
     <string name="concord_members_ban">Ban</string>
+    <string name="concord_members_ban_title">Ban member?</string>
+    <string name="concord_members_ban_message">They can no longer post, and their messages are hidden from everyone. Other apps may remove the community from their list. They can still read new messages until you also remove them from the community. You can unban them later.</string>
     <string name="concord_members_make_admin">Make admin</string>
     <string name="concord_members_remove_admin">Remove admin</string>
     <string name="concord_members_roles_failed">Could not update this member's roles.</string>

commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/screen/loggedIn/chats/publicChannels/concord/ConcordMembersScreen.kt

@@ -63,6 +63,8 @@ import com.vitorpamplona.amethyst.commons.resources.Res
 import com.vitorpamplona.amethyst.commons.resources.back
 import com.vitorpamplona.amethyst.commons.resources.cancel
 import com.vitorpamplona.amethyst.commons.resources.concord_members_ban
+import com.vitorpamplona.amethyst.commons.resources.concord_members_ban_message
+import com.vitorpamplona.amethyst.commons.resources.concord_members_ban_title
 import com.vitorpamplona.amethyst.commons.resources.concord_members_empty
 import com.vitorpamplona.amethyst.commons.resources.concord_members_make_admin
 import com.vitorpamplona.amethyst.commons.resources.concord_members_remove
@@ -92,6 +94,7 @@ import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
 import com.vitorpamplona.quartz.concord.cord04Roles.ConcordPermissions
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import kotlinx.coroutines.flow.MutableStateFlow
+import org.jetbrains.compose.resources.StringResource
 import com.vitorpamplona.amethyst.commons.icons.symbols.Icon as SymbolIcon
 
 /**
@@ -289,9 +292,28 @@ private fun ConcordMemberRow(
         )
     }
 
+    // A ban is reversible here, but not for the banned member: clients such as Armada drop the
+    // community from a banned member's list on sight, so a mis-tap still costs them the community.
+    var confirmBan by remember { mutableStateOf(false) }
+    if (confirmBan) {
+        ConcordConfirmMemberActionDialog(
+            title = Res.string.concord_members_ban_title,
+            message = Res.string.concord_members_ban_message,
+            confirm = Res.string.concord_members_ban,
+            onConfirm = {
+                accountViewModel.setConcordBan(communityId, entry.pubkey, ban = true)
+                confirmBan = false
+            },
+            onDismiss = { confirmBan = false },
+        )
+    }
+
     var confirmRemove by remember { mutableStateOf(false) }
     if (confirmRemove) {
-        ConcordRemoveMemberDialog(
+        ConcordConfirmMemberActionDialog(
+            title = Res.string.concord_members_remove_title,
+            message = Res.string.concord_members_remove_message,
+            confirm = Res.string.concord_members_remove_confirm,
             onConfirm = {
                 accountViewModel.removeConcordMember(communityId, entry.pubkey)
                 confirmRemove = false
@@ -357,7 +379,8 @@ private fun ConcordMemberRow(
                         DropdownMenuItem(
                             text = { Text(stringRes(if (isBanned) Res.string.concord_members_unban else Res.string.concord_members_ban)) },
                             onClick = {
-                                accountViewModel.setConcordBan(communityId, entry.pubkey, ban = !isBanned)
+                                // Unbanning restores access, so only a ban asks first.
+                                if (isBanned) accountViewModel.setConcordBan(communityId, entry.pubkey, ban = false) else confirmBan = true
                                 expanded = false
                             },
                         )
@@ -471,17 +494,20 @@ private fun ConcordRolesDialog(
 
 /** Confirms a hard removal — spells out that it rotates the community key (CORD-06). */
 @Composable
-private fun ConcordRemoveMemberDialog(
+private fun ConcordConfirmMemberActionDialog(
+    title: StringResource,
+    message: StringResource,
+    confirm: StringResource,
     onConfirm: () -> Unit,
     onDismiss: () -> Unit,
 ) {
     AlertDialog(
         onDismissRequest = onDismiss,
-        title = { Text(stringRes(Res.string.concord_members_remove_title)) },
-        text = { Text(stringRes(Res.string.concord_members_remove_message)) },
+        title = { Text(stringRes(title)) },
+        text = { Text(stringRes(message)) },
         confirmButton = {
             TextButton(onClick = onConfirm) {
-                Text(stringRes(Res.string.concord_members_remove_confirm), color = MaterialTheme.colorScheme.error)
+                Text(stringRes(confirm), color = MaterialTheme.colorScheme.error)
             }
         },
         dismissButton = {