fix(deploy): switch matomo to official image 5.10.0

bitnami/matomo was removed from Docker Hub (0 tags). Switch to the
official matomo:5.10.0 image; update port 8080→80, volume path to
/var/www/html, and env var names to match the official image schema.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

deploy/matomo-service.yaml

@@ -9,4 +9,4 @@ spec:
   ports:
     - name: http
       port: 80
-      targetPort: 8080
+      targetPort: 80