fix: tmux-agents v1.7.1 faster popup startup
I shipped v1.7.1 of tmux-agents so prefix + a shows the popup in about 50ms, instead of waiting 0.5–0.7 seconds before anything appears: fzf starts immediately and loads the rows right after. The bigger delay was in my shell, since tmux runs every popup through default-shell -c: my fish config loaded thefuck and mise even for non-interactive shells, costing 0.26–0.47 seconds each time, and now stops early in 0.01–0.02 seconds. I added performance notes, an “If popups feel slow” check in the README and a tmux-agents-perf skill to help agents find where a delay comes from.



