cwkPippa는 Claude의 세 경로를 어떻게 나눠 쓸까

# backend/adapters/base.py — 시스템에서 유일한 추상.
from typing import AsyncIterator, Any
from abc import ABC, abstractmethod

class Adapter(ABC):
    @abstractmethod
    async def stream_turn(
        self,
        *,
        conversation_id: str,
        messages: list[dict[str, Any]],
        system: str,
    ) -> AsyncIterator[dict[str, Any]]:
        ...

# backend/adapters/claude.py — canonical 구현.
# Routes가 직접 import해 — Claude가 곧 canonical shape이고,
# 나머지는 다 downstream에서 specialize.

# backend/services/claude_session.py (sketch)
from claude_agent_sdk import ClaudeSDKClient, ClaudeAgentOptions

_sessions: dict[str, ClaudeSDKClient] = {}

async def get_session(conversation_id: str) -> ClaudeSDKClient:
    if conversation_id not in _sessions:
        client = ClaudeSDKClient(
            options=ClaudeAgentOptions(
                system_prompt={"type": "preset", "preset": "claude_code"},
                # 피파 vault는 시스템 프롬프트로 로드; cwd는 프로젝트 가리킴.
                cwd="/Users/you_username/projects/cwkPippa",
            )
        )
        await client.connect()
        _sessions[conversation_id] = client
    return _sessions[conversation_id]