agent manager 0.40 model and effort pickers that stay current with the CLI

released 0.40 of agent manager. it is a local go/tmux tui for running a few coding agents side by side.

added support for model and effort pickers per session. unlike a lot of other software we fetch the model list dynamically from each CLI so it stays up to date without updating the TUI. a new vendor model shows up without an agent manager release.

also added Antigravity CLI and Oh My Pi as built in agents.

https://github.com/YoanWai/agent-manager/releases/tag/v0.40.0