子代理隔离

@dataclass(frozen=True)
class SubagentRuntimeConfig:
    """Tunable runtime limits for subagent instances."""

    max_subagents: int = 10
    max_concurrent_running: int = 5
    turn_timeout_s: float = TURN_TIMEOUT_S_DEFAULT
    enable_lru_eviction: bool = True
    enable_activity_stream: bool = True
    activity_queue_size: int = 256
    activity_text_max_len: int = 2000
    activity_throttle_ms: float = 500.0
    enable_transcript_stream: bool = True

/// The role name used when a caller omits `agent_type`.
pub const DEFAULT_ROLE_NAME: &str = "default";

#[derive(Default, Serialize)]
struct AgentRoleOverrides {
    developer_instructions: Option<String>,
    model: Option<String>,
    model_reasoning_effort: Option<ReasoningEffort>,
    model_reasoning_summary: Option<ReasoningSummary>,
    model_verbosity: Option<Verbosity>,
    personality: Option<Personality>,
    service_tier: Option<String>,
    features: BTreeMap<String, bool>,
    skills: Option<SkillsConfig>,
}

/// Applies typed role overrides to the existing parent-derived configuration.

packages/subagent/
├── subagent/                    # 共享结果契约
├── subagent-fork-in-process/    # 用父会话已完成轮次播种的进程内子代理
├── subagent-spawn-in-process/   # 干净的进程内子代理
├── subagent-in-process-driver/
├── subagent-acp/                # ACP 协议子代理
├── subagent-dsh-sdk/
├── subagent-claude-code/        # ← 调用官方 Claude Agent SDK
├── subagent-codex/              # ← app-server --stdio 起临时 Codex 线程
├── tool-subagent/               # 暴露给模型的委派工具
├── tool-subagent-control/
└── tool-subagent-report/

# subagent-fork-in-process/README.md:
# "The fork provider creates an in-process child seeded with the parent's
#  completed conversation turns. It shares all run mechanics with spawn;
#  the session seed is the only behavioral difference."

# packages/coding-agent/examples/extensions/subagent/README.md

# Subagent Example

Delegate tasks to specialized subagents with isolated context windows.

## Features

- **Isolated context**: Each subagent runs in a separate `pi` process
- **Streaming output**: See tool calls and progress as they happen
- **Parallel streaming**: All parallel tasks stream updates simultaneously
- **Usage tracking**: Shows turns, tokens, cost, and context usage per agent
- **Abort support**: Ctrl+C propagates to kill subagent processes