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

Dockerfile

@@ -7,6 +7,7 @@ RUN apk add --no-cache \
     rustup \
     upx \
     git \
+    openssh-client \
     wget \
     curl \
     tar \