fix: preserve exchange-qualified tickers across agent prompts

tests/test_ticker_symbol_handling.py

@@ -0,0 +1,18 @@
+import unittest
+
+from cli.utils import normalize_ticker_symbol
+from tradingagents.agents.utils.agent_utils import build_instrument_context
+
+
+class TickerSymbolHandlingTests(unittest.TestCase):
+    def test_normalize_ticker_symbol_preserves_exchange_suffix(self):
+        self.assertEqual(normalize_ticker_symbol(" cnc.to "), "CNC.TO")
+
+    def test_build_instrument_context_mentions_exact_symbol(self):
+        context = build_instrument_context("7203.T")
+        self.assertIn("7203.T", context)
+        self.assertIn("exchange suffix", context)
+
+
+if __name__ == "__main__":
+    unittest.main()