- add PaginationQueryDto<TOrderBy> generic with orderBy and orderDir fields
- add SessionOrderBy, EnvironmentOrderBy, ScenarioOrderBy type aliases
- update session, environment, scenario services and controllers to use typed pagination
- update MCP list_sessions, list_environments, list_scenarios tools to expose orderBy/orderDir
- update tests for all list endpoints to cover page, limit, ordering, and invalid param rejection
- add HttpExceptionFilter logging BadRequestException at warn and InternalServerErrorException at error with cause chain
- add LoggingInterceptor logging request/response pairs at debug level with method, path, body, status, and duration
- extract CodeExecutorService into standalone CodeExecutorModule imported by BrowserModule and McpModule
- thread { cause: err } into all catch blocks across auth, browser, and code-executor services