docs: AGENTS.md repoint to KNEL repos + stale-ref fixes [#769]

Completes dba54b2 (which staged deletions only — pathspec'd add missed
the content edits). Layout table, Key Scripts, DNS discipline, conman
section now point at KNEL/netinfra|facilities|perf|monitoring|inventory;
conman example switched from IP literal to pfv-tsys4 (DNS-names rule).

https://projects.knownelement.com/issues/769#note-4152

scripts/audit-fleet.sh

@@ -19,7 +19,7 @@ set -uo pipefail
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 REMOTE="$REPO_ROOT/tests/remote.sh"
-REMOTE_DNS="$REPO_ROOT/netinfra/dns-cluster-setup/remote-dns.sh"
+REMOTE_DNS="$HOME/projects/KNEL/netinfra/dns-cluster-setup/remote-dns.sh"  # moved to KNEL/netinfra [#769]
 DNS_SUFFIX="knel.net"
 DNS_SERVER="pfv-netinfra-01.knel.net"
 PROX_NODES=(pfv-tsys1 pfv-tsys3 pfv-tsys4 pfv-tsys5 pfv-tsys6 pfv-tsys7 pfv-tsys9)