feat: Add exit UI w/ stats (#924)

packages/cli/src/ui/hooks/slashCommandProcessor.test.ts

@@ -396,6 +396,43 @@ Add any other context about the problem here.
     });
   });
 
+  describe('/quit and /exit commands', () => {
+    beforeEach(() => {
+      vi.useFakeTimers();
+    });
+
+    afterEach(() => {
+      vi.useRealTimers();
+    });
+
+    it.each([['/quit'], ['/exit']])(
+      'should handle %s, add a quit message, and exit the process',
+      async (command) => {
+        const { handleSlashCommand } = getProcessor();
+        const mockDate = new Date('2025-01-01T01:02:03.000Z');
+        vi.setSystemTime(mockDate);
+
+        await act(async () => {
+          handleSlashCommand(command);
+        });
+
+        expect(mockAddItem).toHaveBeenCalledTimes(2);
+        expect(mockAddItem).toHaveBeenNthCalledWith(
+          2,
+          expect.objectContaining({
+            type: MessageType.QUIT,
+            duration: '1h 2m 3s',
+          }),
+          expect.any(Number),
+        );
+
+        // Fast-forward timers to trigger process.exit
+        vi.advanceTimersByTime(100);
+        expect(mockProcessExit).toHaveBeenCalledWith(0);
+      },
+    );
+  });
+
   describe('Unknown command', () => {
     it('should show an error and return true for a general unknown command', async () => {
       const { handleSlashCommand } = getProcessor();