Guard Docker init scripts with existence checks

Prevents errors when Docker Desktop is not installed.

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

zshrc

@@ -130,7 +130,7 @@ export NVM_QUIET=1
 typeset -g POWERLEVEL9K_INSTANT_PROMPT=quiet
 
 # Docker
-source $HOME/.docker/init-zsh.sh || true
+[[ -f "$HOME/.docker/init-zsh.sh" ]] && source "$HOME/.docker/init-zsh.sh"
 
 # iTerm2 integration
 test -e "${HOME}/.iterm2_shell_integration.zsh" && source "${HOME}/.iterm2_shell_integration.zsh"
@@ -157,8 +157,9 @@ alias nowdate='date +"%d-%m-%Y"'
 
 [ -f ~/.fzf.zsh ] && source ~/.fzf.zsh
 
-# The following lines have been added by Docker Desktop to enable Docker CLI completions.
-fpath=($HOME/.docker/completions $fpath)
+# Docker CLI completions
+if [[ -d "$HOME/.docker/completions" ]]; then
+  fpath=($HOME/.docker/completions $fpath)
+fi
 autoload -Uz compinit
 compinit
-# End of Docker CLI completions