fix(gateway): thread agent_team through all 27 lifecycle Context sites

Arms the team-match spec gate that sat in its permissive fallback since
shipping: cell-scoped roles are now rejected on cross-team verbs at the
gateway (a misrouted frontend PM blocked, escalated, and held a backend
task live 2026-07-02). Org-wide roles remain exempt via the policy-side
_ORG_WIDE_ROLES. Test mocks aligned to carry consistent teams.

tests/unit/gateway/test_delegate_project_routing.py

@@ -48,6 +48,7 @@ def _parent(pm_id: Any, product_id: Any = None, project_id: Any = None) -> Magic
         product_id=product_id,
         status="in_progress",
         assigned_to=pm_id,
+        team="backend",
         # delegate obligates the PM's quick_context resumption section.
         quick_context="Decomposition planned; cells implement their slice next.",
     )