Switch adguardhome/esphome/signal-gateway/zigbee2mqtt to PVC storage

Replaces raw hostPath (/srv/data/<app>) with a local-path PVC per app,
so these apps get proper PVC lifecycle semantics and can have a PVC
backup CronJob (matching what gitea already has) instead of being
unbacked host directories. local-path already lives on the same disk
these hostPaths did, so this isn't a storage-tier change.

adguardhome specifically: consolidates the previous split work/+conf/
hostPath mounts into a single PVC mounted at /opt/adguardhome (its own
default convention), since a real deployment can't run two hostPath
subtrees off one PVC.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01566weDFku8TaRC2CJUPVM1

signal-gateway/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: signal-gateway
 description: Signal Gateway Helm chart
 type: application
-version: 0.1.2
+version: 0.1.3
 appVersion: "0.100"
 annotations:
   version-source: github-release:bbernhard/signal-cli-rest-api