chore: fix lint issues in mcp and agent packages

- Fix gci import ordering in manager.go, manager_test.go
- Fix gofmt formatting in loop.go, manager.go, mcp_tool.go, mcp_tool_test.go
- Fix gofumpt formatting in manager_test.go
- Fix golines line length issues in manager.go, mcp_tool_test.go
- Fix wastedassign: replace redundant zero-value init with var declaration in loop.go

pkg/agent/loop.go

@@ -58,7 +58,11 @@ type processOptions struct {
 
 const defaultResponse = "I've completed processing but have no response to give. Increase `max_tool_iterations` in config.json."
 
-func NewAgentLoop(cfg *config.Config, msgBus *bus.MessageBus, provider providers.LLMProvider) *AgentLoop {
+func NewAgentLoop(
+	cfg *config.Config,
+	msgBus *bus.MessageBus,
+	provider providers.LLMProvider,
+) *AgentLoop {
 	registry := NewAgentRegistry(cfg, provider)
 
 	// Register shared tools to all agents
@@ -166,7 +170,7 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 	if al.cfg.Tools.MCP.Enabled {
 		mcpManager := mcp.NewManager()
 		defaultAgent := al.registry.GetDefaultAgent()
-		workspacePath := ""
+		var workspacePath string
 		if defaultAgent != nil && defaultAgent.Workspace != "" {
 			workspacePath = defaultAgent.Workspace
 		} else {
@@ -175,7 +179,7 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 
 		if err := mcpManager.LoadFromMCPConfig(ctx, al.cfg.Tools.MCP, workspacePath); err != nil {
 			logger.WarnCF("agent", "Failed to load MCP servers, MCP tools will not be available",
-				map[string]interface{}{
+				map[string]any{
 					"error": err.Error(),
 				})
 		} else {
@@ -183,7 +187,7 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 			defer func() {
 				if err := mcpManager.Close(); err != nil {
 					logger.ErrorCF("agent", "Failed to close MCP manager",
-						map[string]interface{}{
+						map[string]any{
 							"error": err.Error(),
 						})
 				}
@@ -208,7 +212,7 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 						agent.Tools.Register(mcpTool)
 						totalRegistrations++
 						logger.DebugCF("agent", "Registered MCP tool",
-							map[string]interface{}{
+							map[string]any{
 								"agent_id": agentID,
 								"server":   serverName,
 								"tool":     tool.Name,
@@ -218,7 +222,7 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 				}
 			}
 			logger.InfoCF("agent", "MCP tools registered successfully",
-				map[string]interface{}{
+				map[string]any{
 					"server_count":        len(servers),
 					"unique_tools":        uniqueTools,
 					"total_registrations": totalRegistrations,
@@ -367,7 +371,10 @@ func (al *AgentLoop) RecordLastChatID(chatID string) error {
 	return al.state.SetLastChatID(chatID)
 }
 
-func (al *AgentLoop) ProcessDirect(ctx context.Context, content, sessionKey string) (string, error) {
+func (al *AgentLoop) ProcessDirect(
+	ctx context.Context,
+	content, sessionKey string,
+) (string, error) {
 	return al.ProcessDirectWithChannel(ctx, content, sessionKey, "cli", "direct")
 }
 
@@ -388,7 +395,10 @@ func (al *AgentLoop) ProcessDirectWithChannel(
 
 // ProcessHeartbeat processes a heartbeat request without session history.
 // Each heartbeat is independent and doesn't accumulate context.
-func (al *AgentLoop) ProcessHeartbeat(ctx context.Context, content, channel, chatID string) (string, error) {
+func (al *AgentLoop) ProcessHeartbeat(
+	ctx context.Context,
+	content, channel, chatID string,
+) (string, error) {
 	agent := al.registry.GetDefaultAgent()
 	if agent == nil {
 		return "", fmt.Errorf("no default agent for heartbeat")
@@ -413,13 +423,16 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 	} else {
 		logContent = utils.Truncate(msg.Content, 80)
 	}
-	logger.InfoCF("agent", fmt.Sprintf("Processing message from %s:%s: %s", msg.Channel, msg.SenderID, logContent),
+	logger.InfoCF(
+		"agent",
+		fmt.Sprintf("Processing message from %s:%s: %s", msg.Channel, msg.SenderID, logContent),
 		map[string]any{
 			"channel":     msg.Channel,
 			"chat_id":     msg.ChatID,
 			"sender_id":   msg.SenderID,
 			"session_key": msg.SessionKey,
-		})
+		},
+	)
 
 	// Route system messages to processSystemMessage
 	if msg.Channel == "system" {
@@ -480,9 +493,15 @@ func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage)
 	})
 }
 
-func (al *AgentLoop) processSystemMessage(ctx context.Context, msg bus.InboundMessage) (string, error) {
+func (al *AgentLoop) processSystemMessage(
+	ctx context.Context,
+	msg bus.InboundMessage,
+) (string, error) {
 	if msg.Channel != "system" {
-		return "", fmt.Errorf("processSystemMessage called with non-system message channel: %s", msg.Channel)
+		return "", fmt.Errorf(
+			"processSystemMessage called with non-system message channel: %s",
+			msg.Channel,
+		)
 	}
 
 	logger.InfoCF("agent", "Processing system message",
@@ -540,14 +559,22 @@ func (al *AgentLoop) processSystemMessage(ctx context.Context, msg bus.InboundMe
 }
 
 // runAgentLoop is the core message processing logic.
-func (al *AgentLoop) runAgentLoop(ctx context.Context, agent *AgentInstance, opts processOptions) (string, error) {
+func (al *AgentLoop) runAgentLoop(
+	ctx context.Context,
+	agent *AgentInstance,
+	opts processOptions,
+) (string, error) {
 	// 0. Record last channel for heartbeat notifications (skip internal channels)
 	if opts.Channel != "" && opts.ChatID != "" {
 		// Don't record internal channels (cli, system, subagent)
 		if !constants.IsInternalChannel(opts.Channel) {
 			channelKey := fmt.Sprintf("%s:%s", opts.Channel, opts.ChatID)
 			if err := al.RecordLastChannel(channelKey); err != nil {
-				logger.WarnCF("agent", "Failed to record last channel", map[string]any{"error": err.Error()})
+				logger.WarnCF(
+					"agent",
+					"Failed to record last channel",
+					map[string]any{"error": err.Error()},
+				)
 			}
 		}
 	}
@@ -629,7 +656,10 @@ func (al *AgentLoop) targetReasoningChannelID(channelName string) (chatID string
 	return ""
 }
 
-func (al *AgentLoop) handleReasoning(ctx context.Context, reasoningContent, channelName, channelID string) {
+func (al *AgentLoop) handleReasoning(
+	ctx context.Context,
+	reasoningContent, channelName, channelID string,
+) {
 	if reasoningContent == "" || channelName == "" || channelID == "" {
 		return
 	}
@@ -697,22 +727,33 @@ func (al *AgentLoop) runLLMIteration(
 
 		callLLM := func() (*providers.LLMResponse, error) {
 			if len(agent.Candidates) > 1 && al.fallback != nil {
-				fbResult, fbErr := al.fallback.Execute(ctx, agent.Candidates,
+				fbResult, fbErr := al.fallback.Execute(
+					ctx,
+					agent.Candidates,
 					func(ctx context.Context, provider, model string) (*providers.LLMResponse, error) {
-						return agent.Provider.Chat(ctx, messages, providerToolDefs, model, map[string]any{
-							"max_tokens":       agent.MaxTokens,
-							"temperature":      agent.Temperature,
-							"prompt_cache_key": agent.ID,
-						})
+						return agent.Provider.Chat(
+							ctx,
+							messages,
+							providerToolDefs,
+							model,
+							map[string]any{
+								"max_tokens":       agent.MaxTokens,
+								"temperature":      agent.Temperature,
+								"prompt_cache_key": agent.ID,
+							},
+						)
 					},
 				)
 				if fbErr != nil {
 					return nil, fbErr
 				}
 				if fbResult.Provider != "" && len(fbResult.Attempts) > 0 {
-					logger.InfoCF("agent", fmt.Sprintf("Fallback: succeeded with %s/%s after %d attempts",
-						fbResult.Provider, fbResult.Model, len(fbResult.Attempts)+1),
-						map[string]any{"agent_id": agent.ID, "iteration": iteration})
+					logger.InfoCF(
+						"agent",
+						fmt.Sprintf("Fallback: succeeded with %s/%s after %d attempts",
+							fbResult.Provider, fbResult.Model, len(fbResult.Attempts)+1),
+						map[string]any{"agent_id": agent.ID, "iteration": iteration},
+					)
 				}
 				return fbResult.Response, nil
 			}
@@ -738,10 +779,14 @@ func (al *AgentLoop) runLLMIteration(
 				strings.Contains(errMsg, "length")
 
 			if isContextError && retry < maxRetries {
-				logger.WarnCF("agent", "Context window error detected, attempting compression", map[string]any{
-					"error": err.Error(),
-					"retry": retry,
-				})
+				logger.WarnCF(
+					"agent",
+					"Context window error detected, attempting compression",
+					map[string]any{
+						"error": err.Error(),
+						"retry": retry,
+					},
+				)
 
 				if retry == 0 && !constants.IsInternalChannel(opts.Channel) {
 					al.bus.PublishOutbound(ctx, bus.OutboundMessage{
@@ -773,7 +818,12 @@ func (al *AgentLoop) runLLMIteration(
 			return "", iteration, fmt.Errorf("LLM call failed after retries: %w", err)
 		}
 
-		go al.handleReasoning(ctx, response.Reasoning, opts.Channel, al.targetReasoningChannelID(opts.Channel))
+		go al.handleReasoning(
+			ctx,
+			response.Reasoning,
+			opts.Channel,
+			al.targetReasoningChannelID(opts.Channel),
+		)
 
 		logger.DebugCF("agent", "LLM response",
 			map[string]any{
@@ -1075,7 +1125,11 @@ func formatMessagesForLog(messages []providers.Message) string {
 			for _, tc := range msg.ToolCalls {
 				fmt.Fprintf(&sb, "    - ID: %s, Type: %s, Name: %s\n", tc.ID, tc.Type, tc.Name)
 				if tc.Function != nil {
-					fmt.Fprintf(&sb, "      Arguments: %s\n", utils.Truncate(tc.Function.Arguments, 200))
+					fmt.Fprintf(
+						&sb,
+						"      Arguments: %s\n",
+						utils.Truncate(tc.Function.Arguments, 200),
+					)
 				}
 			}
 		}
@@ -1104,7 +1158,11 @@ func formatToolsForLog(toolDefs []providers.ToolDefinition) string {
 		fmt.Fprintf(&sb, "  [%d] Type: %s, Name: %s\n", i, tool.Type, tool.Function.Name)
 		fmt.Fprintf(&sb, "      Description: %s\n", tool.Function.Description)
 		if len(tool.Function.Parameters) > 0 {
-			fmt.Fprintf(&sb, "      Parameters: %s\n", utils.Truncate(fmt.Sprintf("%v", tool.Function.Parameters), 200))
+			fmt.Fprintf(
+				&sb,
+				"      Parameters: %s\n",
+				utils.Truncate(fmt.Sprintf("%v", tool.Function.Parameters), 200),
+			)
 		}
 	}
 	sb.WriteString("]")
@@ -1201,7 +1259,9 @@ func (al *AgentLoop) summarizeBatch(
 	existingSummary string,
 ) (string, error) {
 	var sb strings.Builder
-	sb.WriteString("Provide a concise summary of this conversation segment, preserving core context and key points.\n")
+	sb.WriteString(
+		"Provide a concise summary of this conversation segment, preserving core context and key points.\n",
+	)
 	if existingSummary != "" {
 		sb.WriteString("Existing context: ")
 		sb.WriteString(existingSummary)