feat: implement v1 consumer API endpoints with runtime_id support (REQ-004~010)

- Generate runtime_id for service-token issuance (CLI and API)
- Implement GET /v1/assets endpoint with asset view and strategy_params
- Implement GET /v1/user_info endpoint with trading_enabled and broker credentials
- Implement POST /v1/assets/{asset_id}/ledger/trades with idempotency support
- Update auth service to support runtime_id tracking and credential encryption
- Add comprehensive test coverage for v1 endpoints (dcy-002 implementation)
- Update postgres repository for ledger and broker credential queries
- Ensure all tests pass for feature validation

app/repositories/portfolio_repository.py

@@ -52,6 +52,7 @@ class PortfolioRepository(Protocol):
         permission: str,
         token_type: str,
         expires_at: datetime | None = None,
+        runtime_id: str | None = None,
     ) -> AuthToken: ...
 
     def list_auth_tokens(self, user_id: str) -> list[AuthToken]: ...