fix: protect log file write and preserve log_states_dict

- Wrap _log_portfolio file I/O in try/except so a write failure
  doesn't discard the analysis results
- Preserve and restore self.log_states_dict in propagate_portfolio()
  alongside ticker and curr_state

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tradingagents/graph/portfolio_analysis.py

@@ -61,7 +61,11 @@ class PortfolioAnalyzer:
             individual_results, trade_date
         )
 
-        self._log_portfolio(trade_date, tickers, individual_results, portfolio_summary)
+        try:
+            self._log_portfolio(trade_date, tickers, individual_results, portfolio_summary)
+        except OSError as e:
+            if debug:
+                print(f"Warning: failed to save portfolio log: {e}")
 
         return {
             "individual_results": individual_results,

tradingagents/graph/trading_graph.py

@@ -283,6 +283,7 @@ class TradingAgentsGraph:
         """
         original_ticker = self.ticker
         original_curr_state = self.curr_state
+        original_log_states = self.log_states_dict.copy()
         try:
             return self.portfolio_analyzer.analyze(
                 tickers, trade_date, self.propagate, debug=self.debug
@@ -290,6 +291,7 @@ class TradingAgentsGraph:
         finally:
             self.ticker = original_ticker
             self.curr_state = original_curr_state
+            self.log_states_dict = original_log_states
 
     def reflect_and_remember(self, returns_losses):
         """Reflect on decisions and update memory based on returns."""