[TMUX/ZSH] Venv improvements

zsh/.zshrc

@@ -176,3 +176,26 @@ zstyle :bracketed-paste-magic paste-finish pastefinish
 ZSH_AUTOSUGGEST_CLEAR_WIDGETS+=(bracketed-paste)
 export PATH=$PATH:/Users/ising/.runai/bin
 source <(/Users/ising/.runai/bin/runai --quiet completion zsh)
+
+# Re-activate an inherited virtualenv — MUST be the last PATH-affecting line.
+#
+# When VIRTUAL_ENV is present in the environment (a tmux pane split carries it
+# in via `-e VIRTUAL_ENV=...`, see .tmux.conf) we source the venv's activate
+# script here rather than in .virtual_env_config.zsh. activate snapshots the
+# current PATH into _OLD_VIRTUAL_PATH and restores it on `deactivate`; if we
+# activated earlier (before .mac_config.zsh, go, runai below all prepend to
+# PATH) that snapshot would be incomplete and `deactivate` would strip
+# ~/.local/bin & friends — dropping claude and co. off PATH. Keeping this last
+# guarantees the snapshot is the fully-built PATH.
+#
+# ANY new PATH mutation must go ABOVE this block.
+#
+# A new tmux window clears the var to empty (`bind c ... -e VIRTUAL_ENV=`) to
+# force the base environment; drop that empty value so nothing sees a bogus venv.
+[ -z "${VIRTUAL_ENV:-}" ] && unset VIRTUAL_ENV
+if [ -n "$VIRTUAL_ENV" ] && [ -f "$VIRTUAL_ENV/bin/activate" ]; then
+    # Guard against double-activation on a manual `source ~/.zshrc`.
+    if [[ ":$PATH:" != *":$VIRTUAL_ENV/bin:"* ]]; then
+        source "$VIRTUAL_ENV/bin/activate"
+    fi
+fi