[TMUX/ZSH] Venv improvements

tmux/.tmux.conf

@@ -27,8 +27,19 @@ bind -T off F12 \
 setw -g mode-keys vi
 set-option -g status-keys vi
 
-bind | split-window -h -c '#{pane_current_path}'
-bind - split-window -v -c '#{pane_current_path}'
+# Splits keep the source pane's cwd AND its active Python venv. #{@venv} is set
+# per-pane by the shell (see .virtual_env_config.zsh); we go through run-shell
+# because tmux expands FORMATS in a run-shell command but NOT in split-window's
+# own -e value. The new pane inherits VIRTUAL_ENV and .zshrc re-activates it;
+# when the source pane has no venv we omit -e so no empty var leaks in. New
+# *windows* deliberately don't inherit it.
+bind | run-shell 'v="#{@venv}"; d="#{pane_current_path}"; if [ -n "$v" ]; then tmux split-window -h -c "$d" -e VIRTUAL_ENV="$v"; else tmux split-window -h -c "$d"; fi'
+bind - run-shell 'v="#{@venv}"; d="#{pane_current_path}"; if [ -n "$v" ]; then tmux split-window -v -c "$d" -e VIRTUAL_ENV="$v"; else tmux split-window -v -c "$d"; fi'
+
+# New windows always start in the base environment: -e clears any inherited
+# VIRTUAL_ENV (e.g. if the tmux server was first started from inside a venv, so
+# its global env carries one), regardless of what the source pane had.
+bind c new-window -e VIRTUAL_ENV=
 
 # Switch windows
 bind-key -n M-Left select-window -t -1