feat: add right-side activity panel for agent status

- Create ActivityPanel component showing per-agent status with
  activity dots, agent names, and contextual status labels
- Add detailPanel slot to AppShell layout (right aside, w-64)
- Move agent activity display from inline ChatPane card to the
  dedicated side panel
- Remove activity prop and inline panel from ChatPane
- Panel appears when a session is selected, hidden on WelcomePane

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/renderer/App.tsx

@@ -1,6 +1,7 @@
 import { useEffect, useMemo, useState } from 'react';
 
 import { AppShell } from '@renderer/components/AppShell';
+import { ActivityPanel } from '@renderer/components/ActivityPanel';
 import { ChatPane } from '@renderer/components/ChatPane';
 import { NewSessionModal } from '@renderer/components/NewSessionModal';
 import { SettingsPanel } from '@renderer/components/SettingsPanel';
@@ -117,6 +118,7 @@ export default function App() {
 
   // Determine main content
   let content: React.ReactNode;
+  let detailPanel: React.ReactNode | undefined;
   if (error) {
     content = (
       <div className="flex h-full items-center justify-center px-8">
@@ -129,13 +131,19 @@ export default function App() {
   } else if (selectedSession && patternForSession && projectForSession) {
     content = (
       <ChatPane
-        activity={activityForSession}
         onSend={(c) => api.sendSessionMessage({ sessionId: selectedSession.id, content: c })}
         pattern={patternForSession}
         project={projectForSession}
         session={selectedSession}
       />
     );
+    detailPanel = (
+      <ActivityPanel
+        activity={activityForSession}
+        pattern={patternForSession}
+        session={selectedSession}
+      />
+    );
   } else {
     content = (
       <WelcomePane
@@ -166,6 +174,7 @@ export default function App() {
     <>
       <AppShell
         content={content}
+        detailPanel={detailPanel}
         overlay={overlay}
         sidebar={
           <Sidebar

src/renderer/components/ActivityPanel.tsx

@@ -0,0 +1,75 @@
+import { useMemo } from 'react';
+import { Activity } from 'lucide-react';
+
+import {
+  buildAgentActivityRows,
+  formatAgentActivityLabel,
+  isAgentActivityActive,
+  isAgentActivityCompleted,
+  type SessionActivityState,
+} from '@renderer/lib/sessionActivity';
+import type { PatternDefinition } from '@shared/domain/pattern';
+import type { SessionRecord } from '@shared/domain/session';
+
+interface ActivityPanelProps {
+  activity?: SessionActivityState;
+  pattern: PatternDefinition;
+  session: SessionRecord;
+}
+
+export function ActivityPanel({ activity, pattern, session }: ActivityPanelProps) {
+  const activityRows = useMemo(
+    () => buildAgentActivityRows(activity, pattern.agents),
+    [activity, pattern.agents],
+  );
+
+  const isBusy = session.status === 'running';
+
+  return (
+    <div className="flex h-full flex-col">
+      {/* Header — top padding clears the title bar overlay zone */}
+      <div className="border-b border-[var(--color-border)] px-4 pb-3 pt-12">
+        <div className="flex items-center gap-2">
+          <Activity className="size-4 text-zinc-500" />
+          <span className="text-[12px] font-semibold uppercase tracking-[0.12em] text-zinc-400">
+            Activity
+          </span>
+          {isBusy && <span className="size-1.5 animate-pulse rounded-full bg-blue-400" />}
+        </div>
+      </div>
+
+      {/* Agent list */}
+      <div className="flex-1 overflow-y-auto px-4 py-3">
+        <div className="space-y-3">
+          {activityRows.map((row) => (
+            <div className="flex items-start gap-2.5" key={row.key}>
+              <span
+                className={`mt-1.5 size-2 shrink-0 rounded-full ${
+                  isAgentActivityActive(row.activity)
+                    ? 'animate-pulse bg-blue-400'
+                    : isAgentActivityCompleted(row.activity)
+                      ? 'bg-emerald-400'
+                      : 'bg-zinc-700'
+                }`}
+              />
+              <div className="min-w-0 flex-1">
+                <div className="truncate text-[12px] font-medium text-zinc-300">
+                  {row.agentName}
+                </div>
+                <div className="truncate text-[12px] text-zinc-500">
+                  {formatAgentActivityLabel(row.activity)}
+                </div>
+              </div>
+            </div>
+          ))}
+        </div>
+
+        {activityRows.length === 0 && (
+          <p className="py-6 text-center text-[12px] text-zinc-600">
+            No agents configured
+          </p>
+        )}
+      </div>
+    </div>
+  );
+}

src/renderer/components/AppShell.tsx

@@ -3,10 +3,11 @@ import type { ReactNode } from 'react';
 interface AppShellProps {
   sidebar: ReactNode;
   content: ReactNode;
+  detailPanel?: ReactNode;
   overlay?: ReactNode;
 }
 
-export function AppShell({ sidebar, content, overlay }: AppShellProps) {
+export function AppShell({ sidebar, content, detailPanel, overlay }: AppShellProps) {
   return (
     <div className="relative flex h-screen bg-[var(--color-surface-0)] text-zinc-100">
       {/* Full-width drag region matching the title bar overlay height */}
@@ -16,6 +17,11 @@ export function AppShell({ sidebar, content, overlay }: AppShellProps) {
         {sidebar}
       </aside>
       <main className="relative min-w-0 flex-1">{content}</main>
+      {detailPanel && (
+        <aside className="flex w-64 shrink-0 flex-col border-l border-[var(--color-border)] bg-[var(--color-surface-1)]">
+          {detailPanel}
+        </aside>
+      )}
       {overlay}
     </div>
   );

src/renderer/components/ChatPane.tsx

@@ -1,13 +1,6 @@
-import { type KeyboardEvent, useEffect, useMemo, useRef, useState } from 'react';
+import { type KeyboardEvent, useEffect, useRef, useState } from 'react';
 import { AlertCircle, ArrowUp, Bot, Loader2, User } from 'lucide-react';
 
-import {
-  buildAgentActivityRows,
-  formatAgentActivityLabel,
-  isAgentActivityActive,
-  isAgentActivityCompleted,
-  type SessionActivityState,
-} from '@renderer/lib/sessionActivity';
 import type { PatternDefinition } from '@shared/domain/pattern';
 import type { ProjectRecord } from '@shared/domain/project';
 import type { SessionRecord } from '@shared/domain/session';
@@ -23,25 +16,18 @@ function ThinkingDots() {
 }
 
 interface ChatPaneProps {
-  activity?: SessionActivityState;
   project: ProjectRecord;
   pattern: PatternDefinition;
   session: SessionRecord;
   onSend: (content: string) => Promise<void>;
 }
 
-export function ChatPane({ activity, project, pattern, session, onSend }: ChatPaneProps) {
+export function ChatPane({ project, pattern, session, onSend }: ChatPaneProps) {
   const [input, setInput] = useState('');
   const transcriptRef = useRef<HTMLDivElement>(null);
   const textareaRef = useRef<HTMLTextAreaElement>(null);
 
   const isBusy = session.status === 'running';
-  const activityRows = useMemo(
-    () => buildAgentActivityRows(activity, pattern.agents),
-    [activity, pattern.agents],
-  );
-  const hasObservedActivity = activityRows.some((row) => !!row.activity);
-  const showActivityPanel = (isBusy || hasObservedActivity) && activityRows.length > 0;
 
   useEffect(() => {
     transcriptRef.current?.scrollTo({
@@ -139,35 +125,6 @@ export function ChatPane({ activity, project, pattern, session, onSend }: ChatPa
                 );
               })}
             </div>
-
-            {showActivityPanel && (
-              <div className="mb-4 rounded-xl border border-zinc-800 bg-zinc-900/60 px-4 py-3">
-                <div className="mb-3 text-[11px] font-semibold uppercase tracking-[0.16em] text-zinc-600">
-                  Agent activity
-                </div>
-                <div className="space-y-2.5">
-                  {activityRows.map((row) => (
-                    <div className="flex items-start gap-3" key={row.key}>
-                      <span
-                        className={`mt-1.5 size-2 shrink-0 rounded-full ${
-                          isAgentActivityActive(row.activity)
-                            ? 'animate-pulse bg-blue-400'
-                            : isAgentActivityCompleted(row.activity)
-                              ? 'bg-emerald-400'
-                              : 'bg-zinc-700'
-                        }`}
-                      />
-                      <div className="min-w-0 flex-1">
-                        <div className="text-[12px] font-medium text-zinc-300">{row.agentName}</div>
-                        <div className="text-[12px] text-zinc-500">
-                          {formatAgentActivityLabel(row.activity)}
-                        </div>
-                      </div>
-                    </div>
-                  ))}
-                </div>
-              </div>
-            )}
           </div>
         )}
       </div>