Remove JSON output to reduce token usage

The text format already provides all necessary information for LLMs
to understand the issue graph. The redundant JSON output was adding
significant token overhead without providing additional value.

The text format includes:
- Graph summary with focus node info and hierarchy
- All nodes with type, state, title, and body preview
- Parent/child relationships
- Related issue connections

Author: SamMorrowDrums

pkg/github/issue_graph.go

@@ -2,7 +2,6 @@ package github
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"regexp"
 	"sort"
@@ -923,18 +922,9 @@ Call this tool early when working on an issue to gather appropriate context abou
 
 			graph := crawler.buildGraph()
 
-			// Format for LLM consumption
+			// Format for LLM consumption - text format is token-efficient and sufficient
 			formattedOutput := formatGraphOutput(graph)
 
-			// Also include JSON for structured access
-			jsonData, err := json.Marshal(graph)
-			if err != nil {
-				return nil, fmt.Errorf("failed to marshal graph: %w", err)
-			}
-
-			// Return both human-readable and JSON format
-			result := fmt.Sprintf("%s\n\nJSON_DATA:\n%s", formattedOutput, string(jsonData))
-
-			return mcp.NewToolResultText(result), nil
+			return mcp.NewToolResultText(formattedOutput), nil
 		}
 }