refactor(k3s): enhance kubeconfig generation and token management

Signed-off-by: Tuan-Dat Tran <tuan-dat.tran@tudattr.dev>

vars/group_vars/k3s/vars.yml

@@ -5,3 +5,6 @@ k3s:
 k3s_primary_server_ip: "{{ groups['k3s_server'] | map('extract', hostvars, 'ansible_default_ipv4') | map(attribute='address') | unique | list | first }}"
 
 k3s_server_name: "k3s.{{ internal_domain }}"
+k3s_cluster_name: homelab
+k3s_user_name: "{{ user }}"
+k3s_context_name: "{{ k3s_cluster_name }}"