homepage: function-first layout + fleet label sweep

Reorganize the gethomepage dashboard from site-based (PFI-ANA, ESH, NH3)
to function-first grouping (Monitoring, AI Systems, Apps, Media, Games,
Infra-<site>, Service Networking). Canonical config now tracked in
configs/homepage/ with Plex/Jellyfin widget keys moved to env
substitution.

Label sweep across fleet compose files:
  - beszel, dozzle, backrest -> Monitoring
  - rest-server-ana -> Service Networking

Healthcheck fixes (previous wget/curl paths broke on distroless +
--private-repos 401):
  - beszel hub:    /beszel health --url ...
  - beszel agent:  /agent health (newly added)
  - rest-server:   nc -z localhost 8000 (TCP probe)

Group name originally "Wiring / Plumbing" collapsed to single-word group
on homepage's parser; renamed to "Service Networking" everywhere.

configs/homepage/settings.yaml

@@ -0,0 +1,43 @@
+---
+# https://gethomepage.dev/latest/configs/settings
+title: ... all my base ...
+theme: dark
+color: slate
+background:
+  image: https://w.wallhaven.cc/full/p9/wallhaven-p9gr2p.jpg
+  blur: sm
+  opacity: 20
+headerStyle: boxedWidgets
+
+providers:
+  openweathermap: openweathermapapikey
+  weatherapi: weatherapiapikey
+
+quicklaunch:
+  searchDescriptions: true
+  hideInternetSearch: true
+  showSearchSuggestions: true
+  hideVisitURL: true
+
+showStats: false
+statusStyle: ""
+
+# Function-first layout. Site-partitioned Infra groups keep the inventory
+# together without mixing app/infra concerns.
+layout:
+  Monitoring:
+    style: row
+    columns: 3
+  AI Systems:
+    style: row
+    columns: 3
+  Apps:
+  Media:
+  Games:
+  UltraSeedbox:
+    style: row
+    columns: 3
+  Infra - ANA:
+  Infra - NH3:
+  Infra - ESH:
+  Service Networking: