feat(mcp): подготовить сервер и доступ к приёмке

backend/drizzle/0019_mcp_recovery.sql

@@ -0,0 +1,7 @@
+BEGIN;
+CREATE TABLE IF NOT EXISTS mcp_operation_checkpoints (
+ operation_id uuid NOT NULL REFERENCES mcp_operations(id), step_index integer NOT NULL,
+ before_sealed text NOT NULL, after_sealed text, created_at timestamptz NOT NULL DEFAULT now(),
+ PRIMARY KEY(operation_id,step_index)
+);
+COMMIT;