Constant DEFAULT_MAX_OUTPUT_BYTES 

pub const DEFAULT_MAX_OUTPUT_BYTES: usize = _; // 16_777_216usize

P5-6 (build brief “cap the buffer like P5-2’s 16MiB caps”): the default per-job bounded-capture ceiling, matching crate::mcp::MCP_MAX_RESPONSE_BYTES’s hardening precedent — generous for real command output while bounding how much memory one background job (let alone max_concurrent of them at once) can force this process to hold.