fix(helm): address CodeRabbit review findings

NOTES.txt:
- Detect ingress scheme dynamically (http/https based on .Values.ingress.tls)
- Include first path in ingress URL output
- Use .Values.service.port in port-forward example instead of hardcoded 80
- Add -n {{ .Release.Namespace }} to all kubectl commands

postiz-config.yaml:
- Merge temporal enabled/external branches: external address now also emits
  TEMPORAL_NAMESPACE and TEMPORAL_TLS, not just TEMPORAL_ADDRESS

temporal-init-job.yaml:
- Use .Values.temporal.postgresql.seeds as PGHOST source (with fallback to
  bitnami sub-chart service name) so init job and runtime use the same host
- Switch to quoted heredoc (<<-'SQL') + psql --set to pass credentials as
  psql variables, preventing shell expansion from breaking on special chars

temporal-secret.yaml:
- Add required validation: temporal.postgresql.password must be set explicitly
  when temporal.enabled=true

values.yaml:
- Remove hardcoded default passwords (postgresPassword, temporal.postgresql.password)
  replaced with empty strings to avoid predictable default credentials

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

charts/postiz/templates/temporal-secret.yaml

@@ -7,7 +7,7 @@ metadata:
     {{- include "postiz.labels" . | nindent 4 }}
 type: Opaque
 data:
-  POSTGRES_PWD: {{ .Values.temporal.postgresql.password | b64enc | quote }}
+  POSTGRES_PWD: {{ required "temporal.postgresql.password is required when temporal.enabled=true" .Values.temporal.postgresql.password | b64enc | quote }}
   {{- if .Values.temporal.apiKey }}
   TEMPORAL_API_KEY: {{ .Values.temporal.apiKey | b64enc | quote }}
   {{- end }}