[ZSH] Speed up shell startup

Move antidote update from every shell start to update_mac.sh: it dropped
the bundle cache each time, forcing a rebuild on the next start. Background
the locale write and skip the brew --repository fork.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

zsh/.mac_config.zsh_mac.example

@@ -1,7 +1,8 @@
 export LC_ALL=en_US.UTF-8
 export LANG=en_US.UTF-8
 export JAVA_HOME=`/usr/libexec/java_home`
-defaults write .GlobalPreferences AppleLocale en_DE
+# macOS resets this on updates (and at random); background it, it's slow
+defaults write .GlobalPreferences AppleLocale en_DE &!
 
 # Set path to work with pycharm ...
 # [[ "$PATH" =~ /usr/local/bin ]] || export PATH=$PATH:/usr/local/bin
@@ -27,7 +28,7 @@ alias tailscale=/Applications/Tailscale.app/Contents/MacOS/Tailscale
 #alias virt-manager="LD_PRELOAD=/opt/homebrew/Cellar/glib/2.86.0/lib virt-manager"
 #alias virt-manager="LD_PRELOAD=/opt/homebrew/Cellar/glib/2.86.0/lib $HOME/python-envs/virt-manager/bin/python3 $HOME/stuff/virt-manager/virt-manager"
 
-HOMEBREW_COMMAND_NOT_FOUND_HANDLER="$(brew --repository)/Library/Homebrew/command-not-found/handler.sh"
+HOMEBREW_COMMAND_NOT_FOUND_HANDLER="${HOMEBREW_REPOSITORY:-$(brew --repository)}/Library/Homebrew/command-not-found/handler.sh"
 if [ -f "$HOMEBREW_COMMAND_NOT_FOUND_HANDLER" ]; then
   source "$HOMEBREW_COMMAND_NOT_FOUND_HANDLER";
 fi