feat(plant): garage PDU current+power via librenms relay; garage dashboard cards [#344]

dashboards/garage.yaml

@@ -18,7 +18,23 @@ views:
             entities:
               - sensor.pfv_garage_temperature
             hours_to_show: 24
+          - type: gauge
+            entity: sensor.pfv_garage_pdu_output_current
+            name: PDU output
+            unit: A
+            min: 0
+            max: 20
+          - type: entity
+            entity: sensor.pfv_garage_pdu_power
+            name: PDU power (est @120V)
+            icon: mdi:flash
+          - type: history-graph
+            title: PDU output (24h)
+            entities:
+              - sensor.pfv_garage_pdu_output_current
+            hours_to_show: 24
           - type: markdown
             content: >
-              **Pending:** garage PDU power + temp (#374 outlet naming,
+              **Pending:** garage PDU outlet naming (#374), minisplit BTU
-              #351 network onboarding), minisplit BTU context (#614).
+              context (#614). Feed via tsys-librenms SNMP relay (AP7830 is
+              v1-only).

packages/plant_snmp.yaml

@@ -312,3 +312,30 @@ sensor:
     value_template: >-
       {% set t = value | regex_findall('(?:^|\n)temp (\d+)') %}
       {{ ((t[1] | float * 9 / 5) + 32) | round(1) if t | length > 1 }}
+
+  # --- Garage PDU (APC AP7830 metered) via tsys-librenms relay [#344] ---
+  # Relay: old PDU speaks SNMPv1 only; tsys-librenms is the sanctioned vantage
+  # (dcinfra/sensors/pdu/garage-pdu-relay.sh in PFVCluster).
+  - platform: snmp
+    name: "PFV garage PDU output current"
+    host: tsys-librenms.knel.net
+    version: 2c
+    community: kn3lmgmt
+    baseoid: .1.3.6.1.4.1.8072.1.3.2.3.1.2.9.103.97.114.97.103.101.112.100.117
+    accept_errors: true
+    device_class: current
+    unit_of_measurement: "A"
+    unique_id: pfv_garage_pdu_amps
+    value_template: >-
+      {% set m = value | regex_findall('output_amps ([0-9.]+)') %}
+      {{ m[0] if m | length > 0 }}
+
+template:
+  - sensor:
+      - name: "PFV garage PDU power"
+        unique_id: pfv_garage_pdu_watts
+        device_class: power
+        unit_of_measurement: "W"
+        state: >-
+          {% set a = states('sensor.pfv_garage_pdu_output_current') | float(-1) %}
+          {{ (a * 120) | round(0) if a >= 0 }}