fix(#648): move Antigravity into the screen-checked group in five more docs

docs/api-reference.md (the signal notes and the idle/working rows), and the
wiki's Notifications-And-Approvals, Keeping-Agents-Running and Troubleshooting
pages, plus docs/grok-integration.md, still called Antigravity's working and
idle status unreliable. It now declares a working line and prompt marker like
Codex, OpenCode, Gemini, Pi and OMP, so only Grok stays on generic cues. The
Troubleshooting entry for a session stuck showing busy also says that an
Antigravity session waiting on a shell-command approval shows busy until it is
answered, and the API reference says the same of its idle signal.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/grok-integration.md

@@ -122,11 +122,11 @@ the remote host, `grok login --device-auth` exists for exactly this.
 ## Known gaps
 
 - **No idle/completion hook yet.** The registry entry declares no `workDetect` prompt
-  marker or working line, which is what gives Codex, OpenCode, Gemini, Pi and OMP a
-  screen check. So Codeman calls a new grok pane idle 3 seconds after launch, and after
+  marker or working line, which is what gives Codex, OpenCode, Gemini, Pi, OMP and
+  Antigravity a screen check. So Codeman calls a new grok pane idle 3 seconds after launch, and after
   that it has only generic cues: Claude's `❯` marker, which grok does not print (see the
   cron item below), and a braille spinner glyph. Working and idle are unreliable for
-  grok, as for Antigravity. Grok has a hooks system, so a Codeman hook POSTing to
+  grok. Grok has a hooks system, so a Codeman hook POSTing to
   `/api/hook-event` is the highest-value follow-up.
 - **No response viewer.** Grok writes ACP JSONL sessions under
   `~/.grok/sessions/<encoded-cwd>/<session-id>/updates.jsonl`; nothing reads them yet.