fix(gateway): inject X-Tool-Server-API-Key header to tools/local fetch restClient

dap-gateway/src/main/java/io/shinhanlife/dap/mcg/presentation/McpRouterController.java

@@ -20,6 +20,7 @@ import io.shinhanlife.dap.lib.adapter.dto.JsonRpcRequest;
 import io.shinhanlife.dap.lib.adapter.dto.JsonRpcResponse;
 import io.shinhanlife.dap.lib.adapter.dto.Params;
 import io.shinhanlife.dap.mcg.config.GatewayFallbackProperties;
+import io.shinhanlife.dap.mcg.config.McpGatewayProperties;
 import io.shinhanlife.dap.mcc.dto.ToolMetadata;
 import io.shinhanlife.dap.mcg.registry.InMemoryRegistryService;
 import io.shinhanlife.dap.mcg.service.ExecuteService;
@@ -60,7 +61,8 @@ public class McpRouterController {
                                ExecuteService executeService,
                                SecurityProperties securityProperties,
                                ObjectMapper objectMapper,
-                               GatewayFallbackProperties gatewayFallbackProperties) {
+                               GatewayFallbackProperties gatewayFallbackProperties,
+                               McpGatewayProperties mcpGatewayProperties) {
         this.registryService = registryService;
         this.executeService = executeService;
         this.securityProperties = securityProperties;
@@ -72,7 +74,15 @@ public class McpRouterController {
         factory.setConnectTimeout(1000); // 연결 시도 타임아웃 1초
         factory.setReadTimeout(1000);    // 응답 대기 타임아웃 1초
         
-        this.restClient = RestClient.builder().requestFactory(factory).build();
+        String apiKey = mcpGatewayProperties.toolServerApiKey();
+        if (apiKey == null || apiKey.isEmpty()) {
+            apiKey = "tool-server-key";
+        }
+        
+        this.restClient = RestClient.builder()
+                .requestFactory(factory)
+                .defaultHeader("X-Tool-Server-API-Key", apiKey)
+                .build();
     }
 
     @PostMapping("/tools/call")