Integrate zosstorage build path and runtime orchestration

Summary:

* add openssh-client to the builder image and mount host SSH keys into the dev container when available

* switch RFS to git builds, register the zosstorage source, and document the extra Rust component

* wire zosstorage into the build: add build_zosstorage(), ship the binary in the initramfs, and extend component validation

* refresh kernel configuration to 6.12.49 while dropping Xen guest selections and enabling counted-by support

* tighten runtime configs: use cached mycelium key path, add zosstorage zinit unit, bootstrap ovsdb-server, and enable openvswitch module

* adjust the network health check ping invocation and fix the RFS pack-tree --debug flag order

* update NOTES changelog, README component list, and introduce a runit helper for qemu/cloud-hypervisor testing

* add ovsdb init script wiring under config/zinit/init and ensure zosstorage is available before mycelium

scripts/rfs/pack-tree.sh

@@ -109,7 +109,7 @@ section "Packing directory to flist"
 log_info "Source path: ${SRC_PATH}"
 log_info "Manifest: ${MANIFEST_PATH}"
 log_info "Store: ${RFS_S3_STORE_URI}"
-safe_execute "${RFS_BIN}" pack --debug -m "${MANIFEST_PATH}" -s "${RFS_S3_STORE_URI}" "${SRC_PATH}"
+safe_execute "${RFS_BIN}" --debug pack  -m "${MANIFEST_PATH}" -s "${RFS_S3_STORE_URI}" "${SRC_PATH}"
 
 section "Patching route.url in manifest to S3 read-only endpoint"
 rfs_common_build_route_url