move PATH to .zshenv so non-interactive shells see it

.zshrc only runs for interactive shells — cron, ssh host-command, and
GUI-launched processes never sourced PATH before. Also includes pending
tmux theme/terminal-overrides work and rsync2/wm aliases.

.zshenv

@@ -0,0 +1,13 @@
+# .zshenv — sourced for every zsh invocation (interactive, non-interactive, scripts).
+# PATH lives here so cron, ssh host-command, and GUI-launched processes see it.
+
+typeset -U path
+path=(
+  /projects/bin
+  $HOME/.local/bin
+  $HOME/.cargo/bin
+  /usr/local/go/bin
+  $HOME/go/bin
+  /opt/homebrew/bin
+  $path
+)