fix: DevTools 工具调用面板字段映射修复 + 清理 TOOL_ENGINE_URL 残留

- 移除 config.js 中已无引用的 TOOL_ENGINE_URL 导出
- 修复工具调用记录时间字段：call.created_at → call.timestamp
- 修复行展开 ID：call.id → call.call_id
- 错误提示从"启动 Tool-Engine"改为"启动 AI-Core"

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

devtools/src/config.js

@@ -56,7 +56,6 @@ const GO_BIN = findGoBin();
 export const DEVTOOLS_PORT = process.env.DEVTOOLS_PORT || 9090;
 export const LOGS_DIR = path.resolve(__dirname, '../logs');
 export const GATEWAY_URL = process.env.GATEWAY_URL || 'http://localhost:8080';
-export const TOOL_ENGINE_URL = process.env.TOOL_ENGINE_URL || 'http://localhost:8092';
 export const PLUGIN_MANAGER_URL = process.env.PLUGIN_MANAGER_URL || 'http://localhost:8094';
 export const ADMIN_USERNAME = process.env.ADMIN_USERNAME || 'admin';
 export const ADMIN_PASSWORD = process.env.ADMIN_PASSWORD || 'cyrene-dev-admin';