Initial commit — Antigravity plugin v0.1.0

Plugin Claude Code miroir du plugin codex officiel d'OpenAI, mais
pour Google Antigravity (agy CLI). Headless via:

  agy --print --dangerously-skip-permissions --print-timeout 10m

Includes:
- 1 forwarder agent (antigravity-rescue)
- 5 slash commands (setup, rescue, status, result, cancel)
- 3 internal skills (cli-runtime, result-handling, gemini-prompting)
- agy-companion.mjs runtime (task / setup / status / result / cancel)
- marketplace.json for `/plugin marketplace add`

Tested: setup OK, foreground task OK, background workflow OK
(except OAuth refresh which requires interactive TTY).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

commands/status.md

@@ -0,0 +1,23 @@
+---
+description: Show status of background Antigravity (agy) tasks
+argument-hint: "[<jobId>] [--json]"
+allowed-tools: Bash(node:*)
+---
+
+Run:
+
+```bash
+node "${CLAUDE_PLUGIN_ROOT}/scripts/agy-companion.mjs" status $ARGUMENTS
+```
+
+Present the output to the user as-is.
+
+If no jobs are found, suggest:
+- Running a foreground task: `/antigravity:rescue <your task>`
+- Or a background task: `/antigravity:rescue --background <your task>`
+
+If a job is shown as `exited`, suggest viewing the result:
+
+```
+/antigravity:result <jobId>
+```