feat(cli): add gemini --resume hint on exit (#16285)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Jack Wotherspoon <jackwoth@google.com>

packages/cli/src/ui/components/SessionSummaryDisplay.tsx

@@ -14,5 +14,9 @@ interface SessionSummaryDisplayProps {
 export const SessionSummaryDisplay: React.FC<SessionSummaryDisplayProps> = ({
   duration,
 }) => (
-  <StatsDisplay title="Agent powering down. Goodbye!" duration={duration} />
+  <StatsDisplay
+    title="Agent powering down. Goodbye!"
+    duration={duration}
+    footer="Tip: Resume a previous session using gemini --resume or /resume"
+  />
 );