fix: Remove DROP TABLE command to preserve trading plan data

src/trading/trading_plan.py

@@ -78,10 +78,7 @@ def create_trading_plan_table():
     """Create the trading plans table if it doesn't exist"""
     with create_client() as client:
         try:
-            # Drop the table if it exists to ensure a clean creation
-            client.command("DROP TABLE IF EXISTS trading_plans")
-            
-            # Create new table with a simple structure
+            # Create new table with a simple structure if it doesn't exist
             query = """
             CREATE TABLE IF NOT EXISTS trading_plans
             (