Refresh hook runtimes after plugin changes (#38703)

## What changed

- Rebuild hook runtimes for loaded sessions when effective plugins change or a marketplace upgrade installs new plugin content.
- Refresh plugin-related caches and MCP runtimes alongside hooks after plugin mutations.
- Preserve each loaded session's current configuration while rebuilding its hooks.

## Testing

- Cover direct plugin upgrades, including subsequent turn and session-end hooks.
- Cover automatic marketplace upgrades for an already loaded session.

GitOrigin-RevId: fef64c68d652f300c7f3d88e81c5017459aa9a18

codex-rs/core/src/session/mod.rs

@@ -1733,6 +1733,10 @@ impl Session {
         };
         self.emit_config_changed_contributors(previous_config.as_ref(), new_config.as_ref());
         self.schedule_mcp_prewarm();
+        self.refresh_hooks(config).await;
+    }
+
+    pub(crate) async fn refresh_hooks(&self, config: Arc<Config>) {
         let environments = self.services.turn_environments.snapshot().await;
         let hooks_config = build_hooks_config(
             config.as_ref(),