open-webui: reach the LLM via the host LAN IP, not the bridge gateway

The bridge gateway (10.89.3.1) lives in the rootless netns; llama-server
runs in the host netns, so the gateway refuses. 192.168.0.143:52625
reaches it through the rootless NAT (verified from the container).
Same LAN-IP pattern the doc already prescribes for the Dankserver
backend.

dankclaw/open-webui/quadlet/open-webui.network

@@ -11,10 +11,12 @@
 # A kernel bridge has no per-container helper, so the failure mode
 # cannot occur.
 #
-# The subnet is pinned so the gateway IP is deterministic: the LLM
-# backend (llama-server :52625, bound 0.0.0.0 on the host) is reached
-# from the container via the gateway. host.containers.internal is a
-# slirp4netns-only name and does not resolve on a bridge.
+# The subnet is pinned so the container's own IP (10.89.3.2) is
+# deterministic. Note the LLM backend is NOT reached via this gateway:
+# the gateway lives in the rootless netns, while llama-server runs in
+# the host netns. The host's LAN IP (192.168.0.143) reaches it through
+# the rootless NAT. host.containers.internal is a slirp4netns-only name
+# and does not resolve on a bridge.
 #
 # Subnet registry on dankclaw (rootless):
 #   10.88.0.0/16  default "podman" bridge