VM101 HMN downloader selector method
Generated UTC: 20260713-192030

Source of code:
- Published Machine Git baseline commit 0cdefcb9bd39e750d200c00f56a3d55c1d18b14a.
- No broad live filesystem inventory was performed.

Access:
- router-ops -> ssh pve-mgts -> VM101 10.71.100.2.
- Existing key on Proxmox: /root/.ssh/pve_to_openwrt_mgts_ed25519.

Deployment:
- raw stdin transport;
- same-directory temporary file;
- exact SHA-256 verification;
- BusyBox ash syntax check;
- root:root and mode 0700;
- atomic mv;
- timestamped rollback copy.

Reused implementation:
- /usr/local/lib/router-egress-vm101-runtime.sh
- vm101_healthy_bootstrap_iface
- vm101_strict_iface
- existing Machine Git v2 publisher
- existing router-machine-close workflow

Verification:
- selector-only harness exits before downloader creates run/config directories;
- auto selection checked;
- explicit caller override checked;
- invalid eth0 request rejected;
- downloader body from TS= onward retains SHA-256 40c52441d31cad02155102bf86fd6583eff605d10d6ae63568e8b67d7911dfa4;
- full refresh and rebalance were not invoked.

Limitations:
- This STEP does not prove a full HideMyName pool download.
- This STEP does not modify hmn-validate-current-pool.sh.
- A controlled full refresh remains a later M07 action after validator alignment.