Harden pod and container security contexts across all workloads

Add securityContext hardening (runAsNonRoot, readOnlyRootFilesystem,
capabilities drop ALL, allowPrivilegeEscalation false) to the 10 workloads
that lacked it: apache-tika, cyberchef, gotenberg, homeassistant,
matrix-delegation-nginx, paperless-server, paperless-consume cronjob
(plus automountServiceAccountToken false), patchmon-frontend,
urlaubsverwaltung and zipline. All contexts are configurable via
securityContext.pod / securityContext.container in values.yaml; writable
paths are provided as emptyDirs. Image-forced deviations (Home Assistant
root start for s6-overlay + NET_RAW for discovery, paperless root init
container for /run ownership) are documented in the charts' values.yaml.
Major version bump for every changed published chart.

gotenberg/templates/deployment.yaml

@@ -16,10 +16,22 @@ spec:
         app: {{ .Release.Name }}-{{ .Chart.Name }}-deployment
     spec:
       automountServiceAccountToken: false
+      securityContext:
+        {{- toYaml .Values.gotenberg.securityContext.pod | nindent 8 }}
       containers:
         - name: {{ .Release.Name }}-{{ .Chart.Name }}-deployment
           image: "gotenberg/gotenberg:{{ .Chart.AppVersion }}"
           imagePullPolicy: IfNotPresent
+          securityContext:
+            {{- toYaml .Values.gotenberg.securityContext.container | nindent 12 }}
+          volumeMounts:
+            # Gotenberg (and the Chromium/LibreOffice it drives) needs writable
+            # /tmp and home directories; with a read-only root filesystem these
+            # are provided as emptyDirs.
+            - name: tmp
+              mountPath: /tmp
+            - name: gotenberg-home
+              mountPath: /home/gotenberg
           ports:
             - containerPort: 3000
               protocol: TCP
@@ -39,4 +51,9 @@ spec:
               memory: "{{ .Values.gotenberg.resources.limits.memory }}"
               cpu: "{{ .Values.gotenberg.resources.limits.cpu }}"
               ephemeral-storage: "{{ .Values.gotenberg.resources.limits.ephemeralStorage }}"
+      volumes:
+        - name: tmp
+          emptyDir: {}
+        - name: gotenberg-home
+          emptyDir: {}
       restartPolicy: Always