Replace Gemini coding agent with Antigravity (#6900)

* Replace Gemini coding agent with Antigravity

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* Remove the dead Gemini mise wrapper in the Antigravity migration

Remove Preinstalls no longer lists gemini, so the wrapper Omarchy created
would have stayed in ~/.local/bin with nothing left to clean it up.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Install Antigravity when it is the default a Gemini user is migrated onto

The opt-out check skipped the install but the rewrite ran anyway, so anyone
who had removed the preinstalls was left with a default agent naming a
command that is not there.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* Fix Antigravity skill provisioning and Gemini wrapper migration

- Wires Omarchy's default skills into Antigravity by linking them to ~/.gemini/config/skills/ in bin/omarchy-provision-user and migrations/1786719479.sh.
- Fixes the Gemini wrapper migration in migrations/1786719479.sh to recognize and remove wrappers containing either `mise use -g "gemini"` or `mise use -g --quiet "gemini"`, while leaving hand-written wrappers intact.
- Adds regression tests for both skill provisioning and wrapper removal in test/shell.d/default-agent-test.sh and test/shell.d/provision-user-test.sh.

* Stop the provisioning test from retheming the session it runs in

The test ran the real omarchy-provision-user, which sources install/user/all.sh and so reached omarchy-theme-set: hyprctl reload against the live compositor, gsettings against the live desktop, and a global Node install, none of which the skill symlinks it asserts need. Its mocks for omarchy-done and omarchy-refresh-applications were shadowed anyway, because provisioning prepends $OMARCHY_PATH/bin ahead of them, so stubbing the install suite at its own path is what a mock cannot do here. The exit status is checked rather than discarded: the assertion held even when provisioning died outright, because the symlinks are made twenty lines before the suite runs.

* Match the Gemini default and wrapper the way Omarchy writes them

The migration decided both questions differently from the code that owns them. It read the default agent with grep -qxF, while omarchy-default-agent takes the first line through read, so a padded "  gemini  " that the launcher still resolves was left naming an agent the launcher no longer supports. The wrapper it deletes was matched anywhere in the file, so a hand-written one that only mentions the installer's line in a comment went with Omarchy's own. Reading it the launcher's way and anchoring the match settles both against whoever wrote the file. The skills loop guards its glob the way migrations/1786539345.sh does, so an empty source cannot leave a symlink named "*" behind a migration already marked complete.

Co-Authored-By: Codex XHigh <noreply@anthropic.com>

* List Antigravity among the skill directories

The manual named Claude Code, Codex, Pi and the generic location; provisioning now links ~/.gemini/config/skills too.

Co-Authored-By: Codex XHigh <noreply@anthropic.com>

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Co-authored-by: David Heinemeier Hansson <david@hey.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: Omabot <omabot@omarchy.org>

bin/omarchy-default-agent

@@ -1,7 +1,7 @@
 #!/bin/bash
 
 # omarchy:summary=Set and launch the default coding agent
-# omarchy:args=[pi|omp|opencode|claude|codex|grok|gemini|copilot|crush]
+# omarchy:args=[pi|omp|opencode|claude|codex|grok|agy|copilot|crush]
 # omarchy:examples=omarchy default agent | omarchy default agent codex | omarchy default agent claude
 
 installing=false
@@ -31,10 +31,10 @@ claude | claude-code) agent="claude"; name="Claude Code" ;;
 codex) agent="codex"; name="Codex" ;;
 crush) agent="crush"; name="Crush" ;;
 grok) agent="grok"; name="Grok"; agent_package="npm:@xai-official/grok" ;;
-gemini | gemini-cli) agent="gemini"; name="Gemini" ;;
+agy | antigravity | antigravity-cli | gemini | gemini-cli) agent="agy"; name="Antigravity"; agent_package="antigravity-cli" ;;
 copilot | github-copilot) agent="copilot"; name="GitHub Copilot" ;;
 *)
-  echo "Usage: omarchy-default-agent <pi|omp|opencode|claude|codex|grok|gemini|copilot|crush>"
+  echo "Usage: omarchy-default-agent <pi|omp|opencode|claude|codex|grok|agy|copilot|crush>"
   exit 1
   ;;
 esac