feat(plex): expose tcp/32400 for remote access via a pinned LoadBalancer VIP

Remote Plex clients had no path in, for two measured reasons: Plex advertised
no remote connection at all (customConnections and ManualPortMappingMode both
ABSENT while PublishServerOnPlexOnlineKey=1), and its Service was ClusterIP, so
32400 had no off-cluster path. The L7 Gateway was NOT the problem -- it serves
Plex correctly (200, claimed=1, 401 on protected endpoints) -- but Plex clients
discover servers through plex.tv, not DNS, so an HTTPRoute cannot put this
server on a client's connection list.

Operator chose the native path over ADVERTISE_IP: Plex terminates its own TLS
with *.plex.direct and streams bypass the Envoy L7 hop.

Adds a hand-written non-catalog unit (the SD schema cannot express a
LoadBalancer Service or a pinned lbipam VIP), registered in render.py's
EXTRA_UNITS so --emit-waves places it in plex's own wave.

externalTrafficPolicy: Cluster, inheriting crafty's 8-day-outage lesson rather
than re-deriving it. Known consequence, documented: SNAT puts remote clients
inside ALLOWED_NETWORKS, so Plex meters them as LAN. Not an auth change.

Remote access does NOT work until the operator does two manual steps that
cannot live in this repo -- the WAN tcp/32400 forward and Plex's "manually
specify public port" toggle (no env var exists for it; verified NONE in the
image's init surface). runbooks/plex-remote-access.md is the procedure.

Touches clusters/** -- a sensitive path -- so the approval-policy stage will
block pending an operator /approve-override.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

clusters/prod/kustomization.yaml

@@ -476,6 +476,26 @@ patches:
       - op: replace
         path: /data/PIHOLE_DNS_VIP
         value: "192.168.2.23"
+      # Plex's remote-access listener VIP — raw tcp/32400 for REMOTE Plex clients
+      # (apps/wave-0/plex-remote.yaml). 192.168.2.24 is the NEXT FREE address in the prod pool
+      # 192.168.2.20-.30, verified live 2026-10-03: the CiliumLoadBalancerIPPool `default-pool`
+      # reported IPsTotal 11 / IPsUsed 4 / IPsAvailable 7, and the only four allocations are .20
+      # (cilium-gateway-shared), .21 (unifi-l4-tcp/-udp), .22 (crafty-l4-tcp/-udp) and .23
+      # (pihole-dns-tcp/-udp). It is inside the pool block the operator already asserted sits outside
+      # the SOHO router's DHCP scope, and it is not a node address (.10/.11/.12) or the
+      # control-plane VIP (.9).
+      #
+      # UNLIKE .23, THIS ONE IS ALSO A WAN PORT-FORWARD TARGET. The router forwards WAN tcp/32400
+      # here, by hand, off-repo — so changing this value is a two-place edit and the router is the
+      # half that CI cannot check. runbooks/plex-remote-access.md is the procedure.
+      #
+      # NOT ARP-PROBED. .23 was verified free with `arping` from a LAN host before it was claimed;
+      # for .24 only the in-cluster pool accounting above was checked, so an off-cluster squatter on
+      # this address would not have been caught. Probe before trusting it if remote access comes up
+      # with a conflict.
+      - op: replace
+        path: /data/PLEX_L4_VIP
+        value: "192.168.2.24"
       # The prod flat LAN. This is the 192.168.2.0/24 segment the SOHO ROUTER at 192.168.2.1 owns —
       # NOT pfSense's 192.168.1.0/24, which is a different network and not in the LAN-DNS path.
       # It scopes the ingress allow for PiHole's DNS listener to LAN clients only.