feat(m28+m29+m30): ACME ARI, email digest, and Helm chart

M28: ACME Renewal Information (RFC 9702) — CA-directed renewal timing
with cert ID computation, directory endpoint discovery, graceful
degradation for non-ARI CAs. 19 tests.

M29: Email notifier wiring + scheduled certificate digest — SMTP
connector bridged to service layer via NotifierAdapter, DigestService
with HTML email template, 7th scheduler loop (24h), digest preview/send
API endpoints and GUI card. 21 tests.

M30: Production-ready Helm chart — server Deployment, PostgreSQL
StatefulSet, agent DaemonSet, ConfigMaps, Secrets, Ingress, security
contexts, health probes, example values for dev/prod/ACME scenarios.

Also: OpenAPI spec updates, MCP tool additions, CI helm-lint job,
documentation updates across 5 doc files and README.

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

deploy/helm/certctl/templates/postgres-secret.yaml

@@ -0,0 +1,15 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: {{ include "certctl.fullname" . }}-postgres
+  labels:
+    {{- include "certctl.labels" . | nindent 4 }}
+    app.kubernetes.io/component: postgres
+type: Opaque
+stringData:
+  {{- if not .Values.postgresql.auth.password }}
+  {{- fail "postgresql.auth.password is required" }}
+  {{- end }}
+  password: {{ .Values.postgresql.auth.password | quote }}
+  username: {{ .Values.postgresql.auth.username | quote }}
+  database: {{ .Values.postgresql.auth.database | quote }}