Add persisted hook enablement state (#19840)

## Why

After `hooks/list` exposes the hook inventory, clients need a way to
persist user hook preferences, make those changes effective in
already-open sessions, and distinguish user-controllable hooks from
managed requirements without adding another bespoke app-server write
API.

## What

- Extends `hooks/list` entries with effective `enabled` state.
- Persists user-level hook state under `hooks.state.<hook-id>` so the
model can grow beyond a single boolean over time.
- Uses the existing `config/batchWrite` path for hook state updates
instead of introducing a dedicated hook write RPC.
- Refreshes live session hook engines after config writes so
already-open threads observe updated enablement without a restart.

## Stack

1. openai/codex#19705
2. openai/codex#19778
3. This PR - openai/codex#19840
4. openai/codex#19882

## Reviewer Notes

The generated schema files account for much of the raw diff. The core
behavior is in:

- `hooks/src/config_rules.rs`, which resolves per-hook user state from
the config layer stack.
- `hooks/src/engine/discovery.rs`, which projects effective enablement
into `hooks/list` from source-derived managedness.
- `config/src/hook_config.rs`, which defines the new `hooks.state`
representation.
- `core/src/session/mod.rs`, which rebuilds live hook state after user
config reloads.

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/app-server-protocol/src/protocol/v2.rs

@@ -472,6 +472,7 @@ v2_enum_from_core!(
         Mdm,
         SessionFlags,
         Plugin,
+        CloudRequirements,
         LegacyManagedConfigFile,
         LegacyManagedConfigMdm,
         Unknown,
@@ -4716,6 +4717,7 @@ pub struct HooksListEntry {
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct HookMetadata {
+    pub key: String,
     pub event_name: HookEventName,
     pub handler_type: HookHandlerType,
     pub matcher: Option<String>,
@@ -4726,6 +4728,8 @@ pub struct HookMetadata {
     pub source: HookSource,
     pub plugin_id: Option<String>,
     pub display_order: i64,
+    pub enabled: bool,
+    pub is_managed: bool,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, JsonSchema, TS)]