Enhance SpotBot balance management after position closure

- Added logic to wait for ETH→USDC swap to settle before refreshing the USDC balance, preventing premature bot stoppage due to low balance.
- Implemented balance verification and cache invalidation for accurate balance checks post-swap.
- Improved logging to indicate the status of balance refresh and cache invalidation after closing a position.

src/Managing.Application/Bots/SpotBot.cs

@@ -1105,6 +1105,31 @@ public class SpotBot : TradingBotBase
                     await VerifyTokenBalanceCleared(closedPosition);
                 }
 
+                // Wait for swap to settle and refresh USDC balance
+                // This prevents the bot from stopping due to "low USDC" before the ETH→USDC swap completes
+                if (!Config.IsForWatchingOnly && Config.TradingType != TradingType.BacktestSpot)
+                {
+                    await LogDebugAsync(
+                        $"⏳ Waiting for swap to settle and refreshing USDC balance...\n" +
+                        $"Position: `{closedPosition.Identifier}`");
+                    
+                    // Wait 3 seconds for the swap to settle on-chain
+                    await Task.Delay(3000);
+                    
+                    // Refresh USDC balance to reflect the swapped tokens
+                    await VerifyAndUpdateBalanceAsync();
+                    
+                    // Invalidate AgentGrain balance cache to force fresh fetch on next balance check
+                    // This ensures the bot won't stop due to "low USDC" using stale cached data
+                    await ServiceScopeHelpers.WithScopedService<IGrainFactory>(_scopeFactory, async grainFactory =>
+                    {
+                        var agentGrain = grainFactory.GetGrain<IAgentGrain>(Account.User.Id);
+                        await agentGrain.ForceUpdateSummaryImmediate();
+                    });
+                    
+                    await LogDebugAsync($"✅ Balance refreshed and cache invalidated after position close");
+                }
+
                 if (tradeClosingPosition)
                 {
                     await SetPositionStatus(signal.Identifier, PositionStatus.Finished);