feat(sessions): add resuming to geminiChat and add CLI flags for session management (#10719)

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

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

@@ -278,7 +278,7 @@ describe('handleAtCommand', () => {
       }),
       125,
     );
-  });
+  }, 10000);
 
   it('should handle multiple @file references', async () => {
     const content1 = 'Content file1';