#445 eq backend unbuilt: hub.mjs has no /eq_* routes + no elazar_questions table — eq CLI POSTs to non-existent endpoints (/eq_ls returns not_found). chat-duo Pending panel reads elazar_questions, so no Elazar question can ever surface. Implement hub-side /eq_add /eq_ls /eq_show /eq_answer /eq_dismiss /eq_stale + elazar_questions schema per eq-spec.md