chore: Save agent ID on exit (#274)

src/cli/App.tsx

@@ -17,7 +17,7 @@ import type { ApprovalResult } from "../agent/approval-execution";
 import { prefetchAvailableModelHandles } from "../agent/available-models";
 import { getResumeData } from "../agent/check-approval";
 import { getClient } from "../agent/client";
-import { setCurrentAgentId } from "../agent/context";
+import { getCurrentAgentId, setCurrentAgentId } from "../agent/context";
 import type { AgentProvenance } from "../agent/create";
 import { sendMessageStream } from "../agent/message";
 import { SessionStats } from "../agent/stats";
@@ -118,6 +118,18 @@ function uid(prefix: string) {
   return `${prefix}-${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 8)}`;
 }
 
+// Save current agent as lastAgent before exiting
+// This ensures subagent overwrites during the session don't persist
+function saveLastAgentBeforeExit() {
+  try {
+    const currentAgentId = getCurrentAgentId();
+    settingsManager.updateLocalProjectSettings({ lastAgent: currentAgentId });
+    settingsManager.updateSettings({ lastAgent: currentAgentId });
+  } catch {
+    // Ignore if no agent context set
+  }
+}
+
 // Get plan mode system reminder if in plan mode
 function getPlanModeReminder(): string {
   if (permissionMode.getMode() !== "plan") {
@@ -1315,6 +1327,7 @@ export default function App({
   );
 
   const handleExit = useCallback(() => {
+    saveLastAgentBeforeExit();
     setShowExitStats(true);
     // Give React time to render the stats, then exit
     setTimeout(() => {
@@ -1721,6 +1734,8 @@ export default function App({
             });
             refreshDerived();
 
+            saveLastAgentBeforeExit();
+
             // Exit after a brief delay to show the message
             setTimeout(() => process.exit(0), 500);
           } catch (error) {

src/cli/components/SessionStats.tsx

@@ -10,6 +10,18 @@ function formatDuration(ms: number): string {
   if (ms < 1000) {
     return `${Math.round(ms)}ms`;
   }
+
+  const totalSeconds = Math.floor(ms / 1000);
+  const hours = Math.floor(totalSeconds / 3600);
+  const minutes = Math.floor((totalSeconds % 3600) / 60);
+  const seconds = totalSeconds % 60;
+
+  if (hours > 0) {
+    return `${hours}h ${minutes}m`;
+  }
+  if (minutes > 0) {
+    return `${minutes}m ${seconds}s`;
+  }
   return `${(ms / 1000).toFixed(1)}s`;
 }
 
@@ -20,15 +32,16 @@ function formatNumber(n: number): string {
 export function SessionStats({ stats, agentId }: SessionStatsProps) {
   const wallDuration = formatDuration(stats.totalWallMs);
   const apiDuration = formatDuration(stats.totalApiMs);
+  const steps = stats.usage.stepCount;
+  const inputTokens = formatNumber(stats.usage.promptTokens);
+  const outputTokens = formatNumber(stats.usage.completionTokens);
 
   return (
     <Box flexDirection="column" paddingTop={1}>
       <Text dimColor>Total duration (API): {apiDuration}</Text>
       <Text dimColor>Total duration (wall): {wallDuration}</Text>
       <Text dimColor>
-        Usage: {stats.usage.stepCount} steps,{" "}
-        {formatNumber(stats.usage.promptTokens)} input,{" "}
-        {formatNumber(stats.usage.completionTokens)} output
+        Usage: {steps} steps · {inputTokens} input · {outputTokens} output
       </Text>
       {agentId && <Text dimColor>Agent ID: {agentId}</Text>}
     </Box>