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- .git history (superseded; legacy repo remains at its original path)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/.gitignore

@@ -0,0 +1,13 @@
+# LOGFILENAME artifacts: the framework (Logging.sh + PrettyPrint.sh) appends
+# every print_info/print_error line to LOGFILENAME, defined as
+# "$0.<Weekday>-YYYY-MM-DD-HH:MM:SS.$$". Running any script that sources the
+# framework therefore drops a timestamped log file next to it. Ignore these
+# everywhere in the repo.
+*.Monday-*
+*.Tuesday-*
+*.Wednesday-*
+*.Thursday-*
+*.Friday-*
+*.Saturday-*
+*.Sunday-*
+dns-cluster-setup/.export/