Two coupled fixes from the 2026-05-08 smoke-test trace:
1. pm_cannot_execute_code is now scoped to i_will_work_on (the
EXECUTION verb) only. Pre-fix it also fired on i_will_plan, which
deadlocked any code-typed parent: cell_pm couldn't plan, so couldn't
transition parent to in_progress, so couldn't delegate. PMs PLAN
code-typed parents and DELEGATE the work — that's exactly the verb
we were blocking.
2. delegate.task_type is now REQUIRED at both the HTTP boundary
(DelegateRequest) and the choreographer dataclass (DelegateInputs).
The pre-fix default of 'code' silently changed semantics whenever a
caller forgot the field — main-pm's call in the smoke trace omitted
it, schema defaulted to 'code', and the cell PM downstream was
wedged. Also drops the choreographer's task.task_type fallback
(the DB column is NOT NULL anyway).
Plus middleware coverage tests for the parallel ServiceError →
4xx handler hierarchy added in the prior session, restoring 100%
coverage across the touched files.
Tests: 3101 passing, 100% coverage, ruff clean.
PARENT_NOT_CLAIMED: Choreographer.delegate now enforces that the parent
task is in_progress AND assigned to the calling PM before allowing
subtask creation. Pre-gateway this was implicit (orchestrator only
spawned PMs after they claimed their parent); the gateway exposes
delegate as a first-class verb so the gate must be explicit.
SUBTASK_CAP: hard-blocks delegation when the parent already has 12
subtasks. Pre-gateway never had this cap because PMs naturally never
created more than a handful per spawn cycle; with delegate as a verb
agents can loop, so a cap is needed.
The _delegate_guard helper was split into _delegate_role_guards,
_delegate_static_guards, and _delegate_lifecycle_guards to keep each
piece below the PLR0911 return-count threshold and make the layered
gating explicit.
Pre-gateway reference: implicit in roboco/runtime/orchestrator.py
spawn flow; restored here as explicit server-side enforcement.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Renn F