huskies: merge 1163 story Replace perm_rx lock-as-presence-signal with a permission router

server/src/chat/transport/slack/commands/mod.rs

@@ -92,8 +92,12 @@ pub(super) async fn handle_incoming_message(
     // If there is a pending permission prompt for this channel, interpret the
     // message as a yes/no response instead of starting a new command/LLM flow.
     {
-        let mut pending = ctx.services.pending_perm_replies.lock().await;
-        if let Some(tx) = pending.remove(channel) {
+        if let Some(tx) = ctx
+            .services
+            .pending_perm_replies
+            .resolve_oldest(channel)
+            .await
+        {
             let decision = if is_permission_approval(message) {
                 PermissionDecision::Approve
             } else {