feat(oam): deploy Smokeping, NetDisco, Oxidized, UNPoller on tsys-librenms [#337][#375]

Deploy OAM monitoring stack on tsys-librenms VM:

- Smokeping: fully operational (port 8081, 16 targets, FPing probing)
- NetDisco: backend+DB+PostgreSQL running (port 8082), all 4 Dell switches
  discovered via SNMP. Web UI blocked by Dancer session_cookie_key config
  issue — needs interactive netdisco-deploy run
- Oxidized: container running (port 8083), deployed with placeholder
  credentials — needs switch login/password to start config backups
- UNPoller: config + docker-compose ready, blocked on Docker image
  availability (image moved from all common registries)
- Weathermap: not yet started (deferred to separate commit)

All configs use DNS names only (no IP literals). All scripts pass
shellcheck via check-rules.sh.

💘 Generated with Crush

Assisted-by: Crush:glm-5.2

oam/oxidized/config

@@ -0,0 +1,38 @@
+---
+username: 'CHANGE_ME'
+password: 'CHANGE_ME'
+model: powerconnect
+interval: 3600
+use_syslog: false
+debug: false
+threads: 30
+timeout: 20
+retries: 3
+prompt: !ruby/regexp /([\w.@-]+[#>]\s?)n/
+rest: 0.0.0.0:8888
+next_adds_job: false
+models: {}
+pid: /home/oxidized/.config/oxidized/pid
+log: /home/oxidized/.config/oxidized/logs/log
+snmp: false
+groups: {}
+models: {}
+resolve_dns: true
+interval: 3600
+output:
+  default: git
+  git:
+    user: oxidized
+    email: oxidized@tsys-librenms.knel.net
+    repo: /home/oxidized/.config/oxidized/git-repos
+source:
+  default: csv
+  csv:
+    file: /home/oxidized/.config/oxidized/router.db
+    delimiter: !ruby/regexp /:/
+    map:
+      name: 0
+      model: 1
+      username: 2
+      password: 3
+    gpg: false