Conventions batch 4: env blocks, homeassistant className default, strict clusterIssuer

- apache-tika, gotenberg, cyberchef, homeassistant, patchmon: additive env
  value blocks rendered through tpl (value, secretKeyRef and configMapKeyRef
  forms), following the template-chart/outline pattern; patchmon gets separate
  blocks for the server container and the guacd sidecar.
- homeassistant: ingress.className now defaults to nginx; an empty className
  omits ingressClassName from the rendered Ingress, so the flexible upstream
  ingress style stays intact.
- outline, paperless-ngx: remove the ingress.clusterIssuer defaults
  (letsencrypt / letsencrypt-issuer) - the value is now strictly required,
  consistent with the repo-wide ingress standard; CI test-values set it
  explicitly.

Chart bumps: apache-tika 7.2.0, gotenberg 4.2.0, cyberchef 5.2.0,
patchmon 5.2.0, homeassistant 4.2.0 (minor); outline 5.0.0,
paperless-ngx 10.0.0 (major).

patchmon/values.yaml

@@ -77,6 +77,10 @@ patchmon:
       periodSeconds: 10
       timeoutSeconds: 5
       failureThreshold: 60
+    # Extra environment variables, appended to the ones the chart always sets.
+    # Values are rendered through tpl; value, secretKeyRef and configMapKeyRef
+    # forms are supported.
+    env: []
   guacd:
     # In-browser RDP for Windows hosts (beta) via the Apache Guacamole daemon,
     # run as a sidecar container in the server pod. Disabled by default; when
@@ -126,6 +130,10 @@ patchmon:
       periodSeconds: 5
       timeoutSeconds: 5
       failureThreshold: 30
+    # Extra environment variables for the guacd sidecar (e.g. GUACD_LOG_LEVEL).
+    # Values are rendered through tpl; value, secretKeyRef and configMapKeyRef
+    # forms are supported.
+    env: []
 
 ingress:
   clusterIssuer: null