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- .git history (superseded; legacy repo remains at its original path)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

scripts/check-rules.sh

@@ -226,7 +226,9 @@ fi
 # ----------------------------------------------------------------------------
 $RULE_VERBOSE && log_step "File hygiene"
 if git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
-    CONFLICT="$(git diff --cached --name-only --diff-filter=ACM 2>/dev/null | xargs -r grep -lE '^(<<<<<<<|=======|>>>>>>>)' 2>/dev/null || true)"
+    # archive/ excluded: legacy files are preserved verbatim and may contain
+    # decorative `====` banners that false-positive as conflict markers.
+    CONFLICT="$(git diff --cached --name-only --diff-filter=ACM 2>/dev/null | grep -v '^archive/' | xargs -r grep -lE '^(<<<<<<<|=======|>>>>>>>)' 2>/dev/null || true)"
     if [ -z "$CONFLICT" ]; then check "No merge-conflict markers staged" "pass"; else check "Merge-conflict markers staged: $CONFLICT" "fail"; fi
 fi