build: add repeatable local release gates

scripts/check-release-local.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+# Run the repository-local release gates. This does not claim production HA,
+# capacity, failover, RPO/RTO, or target-environment approval.
+set -eu
+
+TASK_MAKE=${MAKE:-make}
+
+"$TASK_MAKE" test
+"$TASK_MAKE" vet
+"$TASK_MAKE" build
+"$TASK_MAKE" protocol-check
+"$TASK_MAKE" docs-check
+"$TASK_MAKE" sdk-check
+
+printf '%s\n' '{"status":"local_release_gates_passed","mysql_integration":"run make integration separately","production_acceptance":"target environment evidence still required"}'