agent v0.50.0: NAS network storage Part A1 (NFS/SMB automount foundation)

Host-side NFS/SMB automount of a bulk-media NAS share under /mnt/felhom-drives/<name>
(propagates into the guest via the existing shared bind), the +100000 uid recipe,
per-share liveness, and add/list/remove local-API endpoints. A NAS is a distinct class
that bypasses the drive enroll/eject/decommission/SMART/watchdog machinery.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HxLA1mZurFq9kt8hneFeCs

internal/storage/mountunit.go

@@ -16,6 +16,13 @@ func parseFelhomMountUnit(content string) (MountSpec, bool) {
 	if !strings.Contains(content, felhomUnitMarker) {
 		return MountSpec{}, false
 	}
+	// GUARD (network-storage bypass, Scenario D): a NAS network mount carries the netUnitMarker, which
+	// also contains felhomUnitMarker as a substring. It is NOT a drive — no durable-id, no device — and
+	// MUST NOT be picked up by the host-reboot drive re-assert. Refuse it explicitly here so even a
+	// (contrived) network unit shaped like a by-uuid drive unit can never be classified as a drive.
+	if strings.Contains(content, netUnitMarker) {
+		return MountSpec{}, false
+	}
 	var spec MountSpec
 	for _, line := range strings.Split(content, "\n") {
 		line = strings.TrimSpace(line)