Extract hooks into dedicated crate (#11311)

Summary
- move `core/src/hooks` implementation into a new `codex-hooks` crate
with its own manifest
- update `codex-rs` workspace and `codex-core` crate to depend on the
extracted `hooks` crate and wire up the shared APIs
- ensure references, modules, and lockfile reflect the new crate layout

Testing
- Not run (not requested)

codex-rs/core/src/codex.rs

@@ -27,9 +27,6 @@ use crate::features::FEATURES;
 use crate::features::Feature;
 use crate::features::Features;
 use crate::features::maybe_push_unstable_features_warning;
-use crate::hooks::HookEvent;
-use crate::hooks::HookEventAfterAgent;
-use crate::hooks::Hooks;
 use crate::models_manager::manager::ModelsManager;
 use crate::parse_command::parse_command;
 use crate::parse_turn_item;
@@ -45,6 +42,10 @@ use crate::turn_metadata::resolve_turn_metadata_header_with_timeout;
 use crate::util::error_or_panic;
 use async_channel::Receiver;
 use async_channel::Sender;
+use codex_hooks::HookEvent;
+use codex_hooks::HookEventAfterAgent;
+use codex_hooks::HookPayload;
+use codex_hooks::Hooks;
 use codex_network_proxy::NetworkProxy;
 use codex_protocol::ThreadId;
 use codex_protocol::approvals::ExecPolicyAmendment;
@@ -1102,7 +1103,7 @@ impl Session {
                 Arc::clone(&config),
                 Arc::clone(&auth_manager),
             ),
-            hooks: Hooks::new(config.as_ref()),
+            hooks: Hooks::new(config.notify.clone()),
             rollout: Mutex::new(rollout_recorder),
             user_shell: Arc::new(default_shell),
             shell_snapshot_tx,
@@ -4056,7 +4057,7 @@ pub(crate) async fn run_turn(
                 if !needs_follow_up {
                     last_agent_message = sampling_request_last_agent_message;
                     sess.hooks()
-                        .dispatch(crate::hooks::HookPayload {
+                        .dispatch(HookPayload {
                             session_id: sess.conversation_id,
                             cwd: turn_context.cwd.clone(),
                             triggered_at: chrono::Utc::now(),
@@ -6217,7 +6218,7 @@ mod tests {
                 Arc::clone(&config),
                 Arc::clone(&auth_manager),
             ),
-            hooks: Hooks::new(&config),
+            hooks: Hooks::new(config.notify.clone()),
             rollout: Mutex::new(None),
             user_shell: Arc::new(default_user_shell()),
             shell_snapshot_tx: watch::channel(None).0,
@@ -6352,7 +6353,7 @@ mod tests {
                 Arc::clone(&config),
                 Arc::clone(&auth_manager),
             ),
-            hooks: Hooks::new(&config),
+            hooks: Hooks::new(config.notify.clone()),
             rollout: Mutex::new(None),
             user_shell: Arc::new(default_user_shell()),
             shell_snapshot_tx: watch::channel(None).0,