feat: Add enableSubagents configuration and wire up subagent registration (#9988)

packages/core/src/tools/tool-names.ts

@@ -0,0 +1,17 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// Centralized constants for tool names.
+// This prevents circular dependencies that can occur when other modules (like agents)
+// need to reference a tool's name without importing the tool's implementation.
+
+export const GLOB_TOOL_NAME = 'glob';
+
+// TODO: Migrate other tool names here to follow this pattern and prevent future circular dependencies.
+// Candidates for migration:
+// - LSTool ('list_directory')
+// - ReadFileTool ('read_file')
+// - GrepTool ('search_file_content')