chore(archive): preserve KNELServerBuild remainder + layout notes [#474]

Archive the non-ported remainder of the legacy KNELServerBuild repo
under archive/KNELServerBuild/ with its original structure intact,
completing the legacy repo merge for everything except the live
LibreNMS patterns (ported in the previous commit).

Exclusions:
- .git history (superseded; legacy repo remains at its original path)
- ported files (Agents/librenms, Modules/OAM/oam-librenms.sh,
  ConfigFiles/SNMP/snmp-sudo.conf)
- vendored KNELShellFramework tree (byte-identical duplicate of the
  copy already vendored at vendor/ in this repo)
- SSH authorized-keys files (live access-control material; carrying
  them in an archive invites drift — key policy lives elsewhere)

The whole tree is skip-listed in tests/shellcheck.sh (archived legacy
code, not maintained — same standing as vendor/); check-rules.sh
already prunes archive/. Rule 9 (conflict markers) now also excludes
archive/ staged files: preserved-verbatim legacy scripts contain
decorative "====" banners that false-positive as conflict markers
(same archive exclusion precedent as rule 11).

AGENTS.md: note archive/KNELServerBuild and oam/librenms-agent in the
Repository Layout, and fix the stale KNELIAC path to
/home/reachableceo/projects/KNEL/KNELIAC.

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

archive/KNELServerBuild/ProjectCode/ConfigFiles/DHCP/dhclient.conf

@@ -0,0 +1,14 @@
+option rfc3442-classless-static-routes code 121 = array of unsigned integer 8;
+
+send host-name = gethostname();
+request subnet-mask, broadcast-address, time-offset, routers,
+        domain-name, host-name,
+        domain-name-servers, domain-search, ntp-servers,
+        rfc3442-classless-static-routes;
+
+# Pin DNS and NTP to the redundant pfv-netinfra-01/02 pair regardless of what
+# the DHCP server advertises, so every host on this build uses the same
+# authoritative recursive resolvers and time sources.
+supersede domain-name-servers 192.168.3.252, 192.168.3.253;
+supersede domain-search "knel.net";
+supersede ntp-servers 192.168.3.252, 192.168.3.253;