fix: resolve 429 rate limit errors with API backoff and correct timezone handling for 09:30 candle

main.py

@@ -75,7 +75,7 @@ def run_ticker_lifecycle(client, yf_ticker, t212_ticker, tz):
     if now.hour == 9 and now.minute >= 45:
         logger.info(f"Evaluating opening candle for {yf_ticker}...")
         
-        # Retry loop: wait for yfinance to publish the 09:30-09:45 candle (up to 3 minutes)
+        # Retry loop: wait for yfinance to publish the 09:30-09:45 candle
         setup_found = False
         max_retries = 12
         for attempt in range(max_retries):
@@ -90,19 +90,30 @@ def run_ticker_lifecycle(client, yf_ticker, t212_ticker, tz):
             params = strategy.get_trade_params()
             params['ticker'] = t212_ticker
             
-            # Fetch Account Balance to calculate risk
-            try:
-                account_info = client.get_account_info()
-                virtual_balance = float(os.getenv("VIRTUAL_STARTING_BALANCE", 0))
-                
-                if virtual_balance > 0:
-                    risk_amount = virtual_balance * 0.01
-                else:
-                    available_cash = account_info.get('cash', {}).get('availableToTrade', 1000)
-                    risk_amount = available_cash * 0.01
-            except Exception as e:
-                logger.error(f"Failed to fetch account info for risk calculation: {e}. Defaulting to £2.50 risk.")
-                risk_amount = 2.50
+            # Anti-thundering-herd: Random jitter to prevent 429s from parallel threads
+            import random
+            time.sleep(random.uniform(0.1, 3.0))
+            
+            # Fetch Account Balance to calculate risk with backoff
+            risk_amount = 2.50 # Fallback
+            for attempt in range(3):
+                try:
+                    account_info = client.get_account_info()
+                    virtual_balance = float(os.getenv("VIRTUAL_STARTING_BALANCE", 0))
+                    
+                    if virtual_balance > 0:
+                        risk_amount = virtual_balance * 0.01
+                    else:
+                        available_cash = account_info.get('cash', {}).get('availableToTrade', 1000)
+                        risk_amount = available_cash * 0.01
+                    break # Success
+                except Exception as e:
+                    if '429' in str(e):
+                        logger.warning(f"Rate limited on account fetch for {yf_ticker}. Retrying in {2**(attempt+1)}s...")
+                        time.sleep(2**(attempt+1))
+                    else:
+                        logger.error(f"Failed to fetch account info: {e}. Defaulting to £2.50 risk.")
+                        break
 
             if execution.execute_trade(params, target_risk_amount=risk_amount):
                 # monitor_and_bracket is blocking, wait for fill (times out at 11:00)