M7: release polish — export/import, docs, easy docker push

- Easy docker push (MQTTower ergonomics + the image push it lacks): VERSION file →
  version-tag.yml (semver-guard auto-tag) → docker-publish.yml (buildx multi-arch → GHCR,
  registry centralized for one-line retarget to git.finalfactory.de) + ci.yml + build-and-push.ps1.
- Verified end to end: deploy/Dockerfile builds; docker compose stack (app + timescaledb) comes
  up healthy; /healthz and the dashboard respond in-container.
- JSON config export/import (ExportService) with id remapping on restore + GET /export, POST
  /import endpoints; round-trip test preserves meter→type, meter-scoped tariff, category links.
- README, HA/Tasmota/MQTT wiring guide (docs/wiring.md), Unraid template.
- CLAUDE.md updated to reflect the built codebase.
- i18n: locale-aware number/currency formatting (de-DE); full de UI string localization deferred.

95 tests green (56 Core + 39 integration).

Claude-Session: https://claude.ai/code/session_01WujdMtMJPbxDpDnMeK22rr

deploy/unraid-template.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0"?>
+<!-- Unraid Community Applications template for the MeterVault web app.
+     Requires a reachable PostgreSQL/TimescaleDB (run the timescale/timescaledb container
+     separately, or point ConnectionStrings__Default at an existing instance). -->
+<Container version="2">
+  <Name>MeterVault</Name>
+  <Repository>ghcr.io/finalfactory/metervault:latest</Repository>
+  <Registry>https://ghcr.io/finalfactory/metervault</Registry>
+  <Network>bridge</Network>
+  <Shell>bash</Shell>
+  <Privileged>false</Privileged>
+  <Overview>Self-hosted energy &amp; utility metering: ingest from Home Assistant/Tasmota/MQTT, normalize to consumption, and produce cost dashboards. Needs a TimescaleDB instance.</Overview>
+  <Category>HomeAutomation: Tools: Productivity:</Category>
+  <WebUI>http://[IP]:[PORT:8080]/</WebUI>
+  <Icon>https://raw.githubusercontent.com/FinalFactory/MeterVault/main/docs/icon.png</Icon>
+
+  <Config Name="WebUI Port" Target="8080" Default="8080" Mode="tcp" Description="HTTP port" Type="Port" Display="always" Required="true">8080</Config>
+
+  <Config Name="Database connection" Target="ConnectionStrings__Default" Default="Host=timescaledb;Port=5432;Database=metervault;Username=metervault;Password=changeme" Mode="" Description="PostgreSQL/TimescaleDB connection string" Type="Variable" Display="always" Required="true">Host=timescaledb;Port=5432;Database=metervault;Username=metervault;Password=changeme</Config>
+
+  <Config Name="Time zone" Target="MeterVault__TimeZone" Default="Europe/Berlin" Mode="" Description="IANA timezone for bucketing/display" Type="Variable" Display="always" Required="false">Europe/Berlin</Config>
+
+  <Config Name="API key" Target="MeterVault__ApiKeys__0" Default="" Mode="" Description="API key for the REST API (X-Api-Key header). Leave blank to leave the API open." Type="Variable" Display="always" Required="false" Mask="true"/>
+
+  <Config Name="Reverse-proxy trust" Target="MeterVault__ReverseProxyTrust" Default="false" Mode="" Description="Honour X-Forwarded-User from a trusted auth proxy" Type="Variable" Display="advanced" Required="false">false</Config>
+</Container>