Enhance error handling and logging in BotController, LiveTradingBotGrain, and BotService

- Added specific handling for ServiceUnavailableException in BotController to return user-friendly messages.
- Improved logging for Orleans exceptions in both BotController and BotService to provide clearer context during errors.
- Implemented verification of position closure status in LiveTradingBotGrain, including timeout handling for closing positions.
- Enhanced logging for critical and non-critical operations during bot stop processes to ensure better traceability.

src/Managing.Api/Controllers/BotController.cs

@@ -7,6 +7,7 @@ using Managing.Application.ManageBot.Commands;
 using Managing.Application.Shared;
 using Managing.Common;
 using Managing.Core;
+using Managing.Core.Exceptions;
 using Managing.Domain.Accounts;
 using Managing.Domain.Backtests;
 using Managing.Domain.Bots;
@@ -245,9 +246,26 @@ public class BotController : BaseController
 
             return Ok(result);
         }
+        catch (ServiceUnavailableException ex)
+        {
+            // ServiceUnavailableException is already user-friendly (e.g., from Orleans exception conversion)
+            _logger.LogWarning(ex, "Service unavailable error stopping bot {Identifier}", identifier);
+            return StatusCode(503, ex.Message);
+        }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Error stopping bot");
+            _logger.LogError(ex, "Error stopping bot {Identifier}", identifier);
+            
+            // Check if this is an Orleans exception that wasn't caught earlier
+            if (OrleansExceptionHelper.IsOrleansException(ex))
+            {
+                var userMessage = OrleansExceptionHelper.GetUserFriendlyMessage(ex, "bot stop");
+                _logger.LogWarning(
+                    "Orleans exception detected in controller for bot {Identifier}: {ExceptionType}",
+                    identifier, ex.GetType().Name);
+                return StatusCode(503, userMessage);
+            }
+            
             return StatusCode(500, $"Error stopping bot: {ex.Message}");
         }
     }