feat: add antigravity-cli integration (#2087)

* feat: add antigravity_cli integration harness

Register the `antigravity_cli` target, resolve its configuration
directory to `~/.gemini/antigravity-cli/`, wire target actions,
and add lifecycle hook scripts for Unix and Windows.

* feat: support session resume for antigravity-cli

* fix: correct antigravity-cli hook config path, shape, and agent label

Antigravity CLI reads global customizations from ~/.gemini/config, keys
hooks.json by hook name, and only accepts the matcher/hooks wrapper for
the tool events. The previous install wrote event arrays at the top level
of ~/.gemini/antigravity-cli/hooks.json, which agy never reads and would
reject anyway, so no Herdr hook ever ran.

Session reports were dropped for a third reason: the hooks reported the
agent as antigravity-cli, but the server normalizes that to the canonical
label agy before matching, so is_official_agent_source never matched and
agy --conversation resume was unreachable.

- Resolve the config dir to ~/.gemini/config
- Nest Herdr entries under a Herdr-owned "herdr" block that install
  rewrites and uninstall removes, leaving other named hooks untouched
- Emit grouped entries for PreToolUse/PostToolUse and flat handler lists
  for PreInvocation/PostInvocation/Stop
- Report the canonical agy label from both hook assets and match it in
  agent_resume
- Compile-gate the hook asset constants and stop shadowing $args in the
  PowerShell hook
- Document the real directory, that it must already exist, and the
  named-block behavior

refs #1011
refs #1571

* fix: make antigravity-cli integration session-only

antigravity cli cannot express lifecycle safely: there is no blocked
event, postinvocation is skipped on interruption, and stop fires at the
end of a turn rather than on process exit, which left stale state and
released authority at the wrong time.

report only the conversation on preinvocation and let screen detection
own agent state. resume via `agy --conversation <id>` is unchanged.

* fix: update antigravity session after conversation switch

---------

Co-authored-by: Can Celik <ogulcancelik@gmail.com>

1 files changed, 26 insertions, 1 deletions

diff --git a/src/integration/mod.rs b/src/integration/mod.rs
index b691dce9..045d1bce 100644
--- a/src/integration/mod.rs
+++ b/src/integration/mod.rs
@@ -196,6 +196,32 @@ const QODERCLI_REMOVED_LIFECYCLE_HOOK_EVENTS: [(&str, &str); 12] = [
 const CURSOR_HOOK_INSTALL_NAME: &str = "herdr-agent-state.sh";
 const CURSOR_HOOK_ASSET: &str = include_str!("assets/cursor/herdr-agent-state.sh");
 const CURSOR_INTEGRATION_VERSION: u32 = 1;
+#[cfg(windows)]
+const ANTIGRAVITY_CLI_HOOK_INSTALL_NAME: &str = "herdr-agent-state.ps1";
+#[cfg(not(windows))]
+const ANTIGRAVITY_CLI_HOOK_INSTALL_NAME: &str = "herdr-agent-state.sh";
+#[cfg(windows)]
+const ANTIGRAVITY_CLI_HOOK_ASSET: &str =
+    include_str!("assets/antigravity_cli/herdr-agent-state.ps1");
+#[cfg(not(windows))]
+const ANTIGRAVITY_CLI_HOOK_ASSET: &str =
+    include_str!("assets/antigravity_cli/herdr-agent-state.sh");
+const ANTIGRAVITY_CLI_INTEGRATION_VERSION: u32 = 1;
+/// Antigravity CLI keys `hooks.json` by hook name, so every Herdr entry lives
+/// under one Herdr-owned block that install rewrites and uninstall removes.
+const ANTIGRAVITY_CLI_HOOK_BLOCK_NAME: &str = "herdr";
+const ANTIGRAVITY_CLI_HOOK_TIMEOUT_SEC: u64 = 10;
+/// `(event, reported action)`. Session-only: `PreInvocation` is the only event
+/// we need because it carries `conversationId`. The others cannot express
+/// lifecycle safely — Antigravity CLI has no blocked event, `PostInvocation` is
+/// skipped on interruption, and `Stop` is end-of-turn rather than process exit.
+/// Screen detection owns agent state instead.
+///
+/// `PreInvocation` takes a flat handler list; only the `PreToolUse`/`PostToolUse`
+/// events accept a `matcher`/`hooks` wrapper, and sending one here would
+/// invalidate the whole file.
+const ANTIGRAVITY_CLI_HOOK_EVENTS: [(&str, &str); 1] = [("PreInvocation", "session")];
+const INTEGRATION_VERSION_MARKER: &str = "HERDR_INTEGRATION_VERSION=";
 const MASTRACODE_HOOK_INSTALL_NAME: &str = "herdr-agent-state.sh";
 const MASTRACODE_HOOK_ASSET: &str = include_str!("assets/mastracode/herdr-agent-state.sh");
 const MASTRACODE_INTEGRATION_VERSION: u32 = 2;
@@ -219,7 +245,6 @@ const GROK_HOOK_INSTALL_NAME: &str = "herdr-agent-state.sh";
 const GROK_HOOK_CONFIG_INSTALL_NAME: &str = "herdr.json";
 const GROK_HOOK_ASSET: &str = include_str!("assets/grok/herdr-agent-state.sh");
 const GROK_INTEGRATION_VERSION: u32 = 1;
-const INTEGRATION_VERSION_MARKER: &str = "HERDR_INTEGRATION_VERSION=";
 
 pub(crate) const INSTALL_WARNING_PREFIX: &str = "warning:";