## What happened

Omarchy still installs Gemini CLI and offers it as a default coding agent, but
Google retired Gemini CLI on **18 June 2026**, consolidating its developer CLI
tooling under Antigravity. On that date Gemini CLI and the Gemini Code Assist
IDE extensions stopped serving requests for Google AI Pro/Ultra and free-tier
users; only Gemini Code Assist Standard/Enterprise licences kept access. There
was no soft deprecation and no automatic migration.

References:
- https://developers.googleblog.com/an-important-update-transitioning-gemini-cli-to-antigravity-cli/
- https://github.com/google-gemini/gemini-cli/discussions/27274

A fresh Omarchy install therefore provisions a CLI that cannot serve requests
for most users, and the menu presents it as a working choice.

## Where it lives

1. `install/user/mise.sh:4` — `omarchy-mise-install gemini` installs it on every
   new machine.
2. `default/omarchy/omarchy-menu.jsonc:137` — `setup.default.agent.gemini`
   offers it in the default-agent picker.
3. `bin/omarchy-default-agent` — hardcoded `case` accepts
   `pi|omp|opencode|claude|codex|grok|gemini|copilot|crush`. `gemini` is
   present; there is no `antigravity` entry.
4. `bin/omarchy-agent` — a second hardcoded `case` maps each agent to its
   unattended launch flags (`gemini) command=(gemini --yolo)`). Also has no
   `antigravity` entry.

Because both `case` statements live in package-owned `/usr/share/omarchy/bin`,
a user cannot select Antigravity CLI as their default agent locally without
editing files that `omarchy update` overwrites.

## Removing it locally does not stick

`omarchy-mise-install` does not install the tool directly — it writes a
self-healing wrapper to `~/.local/bin/<command>`:

```bash
#!/bin/bash
export MISE_MINIMUM_RELEASE_AGE=0
mise use -g --quiet "gemini" || exit 1
exec mise x "gemini" -- "gemini" "$@"
```

So `mise uninstall gemini` is undone the next time anything *runs* `gemini`:
the wrapper re-adds it to `~/.config/mise/config.toml` and reinstalls it.

That is easy to trigger by accident. A user who previously selected Gemini
still has `gemini` in `~/.config/omarchy/defaults/agent`, so the agent
keybinding calls `omarchy-agent` -> `omarchy-cmd-missing gemini` sees the
wrapper and considers the command present -> launches `gemini --yolo` -> the
wrapper silently reinstalls the retired CLI. I hit exactly this: gemini was
uninstalled, and reappeared in mise's global config about 15 minutes later.

Fully removing it locally takes three steps — delete `~/.local/bin/gemini`,
repoint `~/.config/omarchy/defaults/agent`, then `mise use -g --rm gemini &&
mise uninstall gemini` — and even then `omarchy update` recreates the wrapper
via `install/user/mise.sh`.

## Expected

- Omarchy stops installing `gemini` by default.
- Antigravity CLI is selectable as a default coding agent.

## Suggested fix

`antigravity-cli` is already in mise's registry as
`aqua:google-antigravity/antigravity-cli` (binary `agy`, currently 1.1.22), so
it drops into the existing tooling:

- `install/user/mise.sh`: replace `omarchy-mise-install gemini` with
  `omarchy-mise-install antigravity-cli`.
- `bin/omarchy-default-agent`: add an
  `antigravity | antigravity-cli | agy) agent="antigravity"; name="Antigravity";
  agent_package="antigravity-cli" ;;` branch, and update the usage string and
  the `omarchy:args=` summary comment.
- `bin/omarchy-agent`: add the matching launch case with Antigravity's
  unattended flag.
- `default/omarchy/omarchy-menu.jsonc`: replace the `setup.default.agent.gemini`
  entry with an Antigravity one.
- A migration for existing installs, which needs to do more than drop the
  install line:
  - remove the `~/.local/bin/gemini` wrapper, or it will keep reinstalling the
    retired CLI on every invocation;
  - rewrite `~/.config/omarchy/defaults/agent` for users who selected `gemini`,
    since `omarchy-agent` otherwise fails with "Unsupported default agent" once
    the case is removed;
  - `mise use -g --rm gemini && mise uninstall gemini` to clear the tool itself.

Note that Gemini CLI and Antigravity CLI are separate tools rather than a rename,
so this is a swap plus a migration, not a version bump.

## System details

- Omarchy version: 4.0.2-1
- Arch Linux, Hyprland (Wayland)
- Affected regardless of hardware; this is a packaging/tooling issue.