feat: show agent model, effort, and description in activity panel

Each agent now renders as a card with:
- Status dot and name
- Model badge (e.g. gpt-5.4) and reasoning effort badge
- Agent description text
- Live activity status label
Cards highlight with blue/emerald borders when active/completed.

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

src/renderer/components/ActivityPanel.tsx

@@ -1,5 +1,5 @@
 import { useMemo } from 'react';
-import { Activity } from 'lucide-react';
+import { Activity, Bot, Cpu, Sparkles } from 'lucide-react';
 
 import {
   buildAgentActivityRows,
@@ -11,6 +11,21 @@ import {
 import type { PatternDefinition } from '@shared/domain/pattern';
 import type { SessionRecord } from '@shared/domain/session';
 
+function formatModel(model: string): string {
+  return model.replace(/-/g, '\u2011');
+}
+
+function formatEffort(effort: string | undefined): string | undefined {
+  if (!effort) return undefined;
+  const labels: Record<string, string> = {
+    low: 'Low effort',
+    medium: 'Medium effort',
+    high: 'High effort',
+    xhigh: 'Max effort',
+  };
+  return labels[effort] ?? effort;
+}
+
 interface ActivityPanelProps {
   activity?: SessionActivityState;
   pattern: PatternDefinition;
@@ -38,30 +53,82 @@ export function ActivityPanel({ activity, pattern, session }: ActivityPanelProps
         </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'
+      {/* Agent cards */}
+      <div className="flex-1 overflow-y-auto px-3 py-3">
+        <div className="space-y-2">
+          {activityRows.map((row, index) => {
+            const agent = pattern.agents[index];
+            const isActive = isAgentActivityActive(row.activity);
+            const isCompleted = isAgentActivityCompleted(row.activity);
+
+            return (
+              <div
+                className={`rounded-lg border px-3 py-2.5 transition-colors ${
+                  isActive
+                    ? 'border-blue-500/20 bg-blue-500/5'
+                    : isCompleted
+                      ? 'border-emerald-500/15 bg-emerald-500/5'
+                      : 'border-zinc-800 bg-zinc-900/40'
                 }`}
-              />
-              <div className="min-w-0 flex-1">
-                <div className="truncate text-[12px] font-medium text-zinc-300">
-                  {row.agentName}
+                key={row.key}
+              >
+                {/* Agent name + status dot */}
+                <div className="flex items-center gap-2">
+                  <span
+                    className={`size-2 shrink-0 rounded-full ${
+                      isActive
+                        ? 'animate-pulse bg-blue-400'
+                        : isCompleted
+                          ? 'bg-emerald-400'
+                          : 'bg-zinc-700'
+                    }`}
+                  />
+                  <span className="truncate text-[12px] font-semibold text-zinc-200">
+                    {row.agentName}
+                  </span>
                 </div>
-                <div className="truncate text-[12px] text-zinc-500">
-                  {formatAgentActivityLabel(row.activity)}
+
+                {/* Model + reasoning effort badges */}
+                {agent && (
+                  <div className="mt-1.5 flex flex-wrap items-center gap-1.5">
+                    <span className="inline-flex items-center gap-1 rounded bg-zinc-800 px-1.5 py-0.5 text-[10px] font-medium text-zinc-400">
+                      <Cpu className="size-2.5" />
+                      {formatModel(agent.model)}
+                    </span>
+                    {agent.reasoningEffort && (
+                      <span className="inline-flex items-center gap-1 rounded bg-zinc-800 px-1.5 py-0.5 text-[10px] font-medium text-zinc-400">
+                        <Sparkles className="size-2.5" />
+                        {formatEffort(agent.reasoningEffort)}
+                      </span>
+                    )}
+                  </div>
+                )}
+
+                {/* Description */}
+                {agent?.description && (
+                  <p className="mt-1.5 text-[11px] leading-relaxed text-zinc-500">
+                    {agent.description}
+                  </p>
+                )}
+
+                {/* Activity status */}
+                <div className="mt-2 flex items-center gap-1.5">
+                  <Bot className="size-3 text-zinc-600" />
+                  <span
+                    className={`text-[11px] ${
+                      isActive
+                        ? 'text-blue-400'
+                        : isCompleted
+                          ? 'text-emerald-400'
+                          : 'text-zinc-600'
+                    }`}
+                  >
+                    {formatAgentActivityLabel(row.activity)}
+                  </span>
                 </div>
               </div>
-            </div>
-          ))}
+            );
+          })}
         </div>
 
         {activityRows.length === 0 && (
@@ -73,3 +140,4 @@ export function ActivityPanel({ activity, pattern, session }: ActivityPanelProps
     </div>
   );
 }
+