feat: add usage tracking, output mode, and cli exit mode (#7)

src/cli/components/InputRich.tsx

@@ -26,6 +26,7 @@ export function Input({
   onSubmit,
   permissionMode: externalMode,
   onPermissionModeChange,
+  onExit,
 }: {
   visible?: boolean;
   streaming: boolean;
@@ -35,6 +36,7 @@ export function Input({
   onSubmit: (message?: string) => void;
   permissionMode?: PermissionMode;
   onPermissionModeChange?: (mode: PermissionMode) => void;
+  onExit?: () => void;
 }) {
   const [value, setValue] = useState("");
   const [escapePressed, setEscapePressed] = useState(false);
@@ -84,7 +86,8 @@ export function Input({
   useInput((input, key) => {
     if (input === "c" && key.ctrl) {
       if (ctrlCPressed) {
-        // Second CTRL-C - exit application
+        // Second CTRL-C - call onExit callback then exit application
+        if (onExit) onExit();
         process.exit(0);
       } else {
         // First CTRL-C - start 1-second timer
@@ -209,7 +212,7 @@ export function Input({
               message={thinkingMessage}
               shimmerOffset={shimmerOffset}
             />
-            {shouldShowTokenCount && <Text dimColor> ({tokenCount}↑)</Text>}
+            {shouldShowTokenCount && <Text dimColor> ({tokenCount} ↑)</Text>}
           </Box>
         </Box>
       )}

src/cli/components/SessionStats.tsx

@@ -0,0 +1,34 @@
+import { Box, Text } from "ink";
+import type { SessionStatsSnapshot } from "../../agent/stats";
+
+interface SessionStatsProps {
+  stats: SessionStatsSnapshot;
+}
+
+function formatDuration(ms: number): string {
+  if (ms < 1000) {
+    return `${Math.round(ms)}ms`;
+  }
+  return `${(ms / 1000).toFixed(1)}s`;
+}
+
+function formatNumber(n: number): string {
+  return n.toLocaleString();
+}
+
+export function SessionStats({ stats }: SessionStatsProps) {
+  const wallDuration = formatDuration(stats.totalWallMs);
+  const apiDuration = formatDuration(stats.totalApiMs);
+
+  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
+      </Text>
+    </Box>
+  );
+}