urlaubsverwaltung chart: naming scheme, configurable probes, flexible ingress

- Rename all resources from <chart>-<release>-uv-<kind> to the repo
  standard <release>-<chart>-<kind> (deployment, service, ingress, both
  OnePasswordItem secrets); drop the uv infix. No PVCs in this chart, so
  no storage migration is needed.
- TLS secret renamed to the standard tls-<release>-<chart>-ingress
  (was tls-<chart>-<release>-ingress).
- Probes lifted into values (urlaubsverwaltung.livenessProbe/
  readinessProbe/startupProbe); defaults are exactly the previously
  hardcoded, issue-#9-calibrated settings.
- Repo-standard flexible ingress: ingress.className (default nginx),
  ingress.annotations merged with the cert-manager annotation,
  ingress.enabled flag; domain/clusterIssuer stay required.
- Additive urlaubsverwaltung.env block rendered through tpl with
  value/secretKeyRef/configMapKeyRef forms.
- CI fixtures updated to the new secret names.

Major bump 4.1.2+up6.7.0 -> 5.0.0+up6.7.0 (resource renames).

urlaubsverwaltung/templates/urlaubsverwaltung-db.secret.yaml

@@ -1,6 +1,6 @@
 apiVersion: onepassword.com/v1
 kind: OnePasswordItem
 metadata:
-  name: {{ .Chart.Name }}-{{ .Release.Name }}-uv-db-secret
+  name: {{ .Release.Name }}-{{ .Chart.Name }}-db-secret
 spec:
   itemPath: {{ .Values.secrets.databaseSecretRef }}