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/state/service.rs

@@ -8,13 +8,13 @@ use crate::client::ModelClient;
 use crate::config::StartedNetworkProxy;
 use crate::exec_policy::ExecPolicyManager;
 use crate::file_watcher::FileWatcher;
-use crate::hooks::Hooks;
 use crate::mcp_connection_manager::McpConnectionManager;
 use crate::models_manager::manager::ModelsManager;
 use crate::skills::SkillsManager;
 use crate::state_db::StateDbHandle;
 use crate::tools::sandboxing::ApprovalStore;
 use crate::unified_exec::UnifiedExecProcessManager;
+use codex_hooks::Hooks;
 use codex_otel::OtelManager;
 use tokio::sync::Mutex;
 use tokio::sync::RwLock;