Kibana failed to start

You have duplicated values. Replace at end:

server.ssl.enabled: true
server.ssl.certificate: /etc/kibana/kibana-server.crt
server.ssl.key: /etc/kibana/kibana-server.key
server.publicBaseUrl: "https://kali-purple.kali.purple:5601"
server.ssl.enabled: true
server.ssl.certificate: /etc/kibana/kibana-server.crt
server.ssl.key: /etc/kibana/kibana-server.key
server.publicBaseUrl: "https://kali-purple.kali.purple:5601"
server.host: "kali-purple.kali.purple"
server.host: "kali-purple.kali.purple"
server.host: "kali-purple.kali.purple"

with

server.ssl.enabled: true
server.ssl.certificate: /etc/kibana/kibana-server.crt
server.ssl.key: /etc/kibana/kibana-server.key
server.publicBaseUrl: "https://kali-purple.kali.purple:5601"