use USER env var in starship prompt instead of system user

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

src/servers/api/terminal/templates/starship-officer.toml

@@ -1,10 +1,8 @@
-format = "$username:$hostname $directory $character"
+format = "$env_var_USER:$hostname $directory $character"
 
-[username]
-show_always = true
-format = "[$user]($style)"
-style_user = "bold #0891B2"
-style_root = "bold red"
+[env_var.USER]
+format = "[$env_value]($style)"
+style = "bold #0891B2"
 
 [hostname]
 ssh_only = false