Hold agent activation in its loading state until the agent responds

Clicking Activate reverted to idle (with a success toast) as soon as
the start API returned — but a launched process is not a responding
agent, so the card lingered and read as a failed activation. The card's
button now stays in its loading state from click until the chat's turn
actually starts (the card unmounts then), with a 60s give-up window,
and the copy switches to "Starting {agent}… It will pick up your
message as soon as it connects." The premature success toast is gone —
the agent visibly starting work is the confirmation.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

desktop/src/features/chats/ui/ChatConversationRows.tsx

@@ -232,11 +232,14 @@ export function AgentActivationCard({
               </div>
               <div className="min-w-0">
                 <p className="text-sm font-medium">
-                  Activate {agentName} to get a response
+                  {isActivating
+                    ? `Starting ${agentName}…`
+                    : `Activate ${agentName} to get a response`}
                 </p>
                 <p className="mt-1 text-sm text-muted-foreground">
-                  Your message was sent, but this agent is not active in this
-                  chat yet.
+                  {isActivating
+                    ? "It will pick up your message as soon as it connects."
+                    : "Your message was sent, but this agent is not active in this chat yet."}
                 </p>
               </div>
             </div>

desktop/src/features/chats/ui/ChatDetail.tsx

@@ -470,6 +470,30 @@ export function ChatDetail({
   // message, and start its turn. Without this grace window the card re-shows
   // ~1s after activation and reads as "activation didn't work".
   const AGENT_ACTIVATION_GRACE_MS = 20_000;
+  // "Activated" isn't done until the agent responds: the card's button holds
+  // its loading state from click until this chat has a live turn (the card
+  // unmounts then) or the give-up window expires — the start API returning
+  // only means the process launched, not that it's connected and replaying
+  // the pending message.
+  const ACTIVATION_PENDING_MS = 60_000;
+  const [isActivationPending, setIsActivationPending] = React.useState(false);
+  const handleActivateAgent = React.useCallback(() => {
+    setIsActivationPending(true);
+    onActivateAgent();
+  }, [onActivateAgent]);
+  React.useEffect(() => {
+    if (!isActivationPending) {
+      return;
+    }
+    if (isChatTurnActive) {
+      setIsActivationPending(false);
+      return;
+    }
+    const timeout = window.setTimeout(() => {
+      setIsActivationPending(false);
+    }, ACTIVATION_PENDING_MS);
+    return () => window.clearTimeout(timeout);
+  }, [isActivationPending, isChatTurnActive]);
   const [activationGraceUntil, setActivationGraceUntil] = React.useState(0);
   const wasActivatingRef = React.useRef(false);
   React.useEffect(() => {
@@ -620,8 +644,10 @@ export function ChatDetail({
                               >
                                 <AgentActivationCard
                                   agentName={defaultAgent?.name ?? "Fizz"}
-                                  isActivating={isActivatingAgent}
-                                  onActivate={onActivateAgent}
+                                  isActivating={
+                                    isActivatingAgent || isActivationPending
+                                  }
+                                  onActivate={handleActivateAgent}
                                 />
                               </MessageScrollerItem>
                             ) : null}

desktop/src/features/chats/ui/ChatsScreen.tsx

@@ -516,10 +516,10 @@ export function ChatsScreen({
           defaultAgent.status !== "running" &&
           defaultAgent.status !== "deployed"
         ) {
-          const updatedAgent = await startManagedAgentMutation.mutateAsync(
-            defaultAgent.pubkey,
-          );
-          toast.success(`${updatedAgent.name || defaultAgent.name} activated`);
+          // No success toast: the process starting is not the same as the
+          // agent responding — the activation card holds its loading state
+          // until the agent's turn actually begins.
+          await startManagedAgentMutation.mutateAsync(defaultAgent.pubkey);
         } else {
           await managedAgentsQuery.refetch();
           toast.success(`${defaultAgent.name} activated`);