fix(beszel): GPU-LXC temperature alerts watch the GPU, not the hypervisor CPU

nh3-ml1's first Temperature alert (2026-09-25 2105, 88.8 C) was nh3-pve's CPU
package during the nightly vzdump; the GPU sat at 47 C. hwmon is not namespaced,
so an LXC's agent reports its host's coretemp sensors under the LXC's name.

- hosts/{nh3,esh}-ml1.yaml: SENSORS=-coretemp_*,acpitz (blacklist); GPU and
  NVMe temperatures verified still reported.
- Hub: Temperature >95 C / 5 m on nh3-pve and esh-pve for the CPUs (i9-13900H
  TjMax 100 C; nh3-pve 2-hour averages reach 88 C on busy days).
- nh3-pve README: runs warmer than esh-pve; workload confounds it, check
  airflow on the next visit.

stacks/beszel/hosts/esh-ml1.yaml

@@ -5,6 +5,13 @@
 services:
   beszel-agent:
     image: henrygd/beszel-agent-nvidia:0.18.7
+    environment:
+      # Drop the HYPERVISOR's CPU sensors. An LXC reads the host's hwmon, so
+      # without this the Temperature alert here fires on the host CPU and is
+      # labelled as this GPU box (nh3-ml1, 2026-09-25 2100: "88.8 °C" = nh3-pve's
+      # package during vzdump, GPU at 47 °C). The GPU and NVMe temps stay; the
+      # host's own Beszel system alerts on its CPU.
+      - SENSORS=-coretemp_*,acpitz
     deploy:
       resources:
         reservations:

stacks/beszel/hosts/nh3-ml1.yaml

@@ -6,6 +6,13 @@
 services:
   beszel-agent:
     image: henrygd/beszel-agent-nvidia:0.18.7
+    environment:
+      # Drop the HYPERVISOR's CPU sensors. An LXC reads the host's hwmon, so
+      # without this the Temperature alert here fires on the host CPU and is
+      # labelled as this GPU box (nh3-ml1, 2026-09-25 2100: "88.8 °C" = nh3-pve's
+      # package during vzdump, GPU at 47 °C). The GPU and NVMe temps stay; the
+      # host's own Beszel system alerts on its CPU.
+      - SENSORS=-coretemp_*,acpitz
     deploy:
       resources:
         reservations: