Plugin hooks modules recover better from failing and crashing plugins

What

Plugins can supply hooks modules, code that runs when certain events happen in Claude Code, inside a separate background process called the hooks worker. How failures there are handled changed:

• Build retries: when the modules are built, Claude Code now tracks which modules were pushed out by another and which failed. It retries without the pushed-out one and records why each unloaded module failed. Before, the first failed hook unloaded its module and the build was repeated.
• Worker crashes: if the hooks worker dies while a hook is running, the plugin now stays loaded and the worker is replaced, so the hook's .catch can still run. Before, the plugin was unloaded with "was unloaded: it crashed the hooks worker".
• New errors for plugin authors: user-tier plugins that never call engine.create, or that withhold or replace another plugin's $. names, now throw errors.
• __proto__ warning: a plugin that copies $ by assignment loses __proto__, and a warning now says so.

Why

One misbehaving plugin is less likely to take others down with it, and a crash no longer unloads the plugin outright. Plugin authors may see new errors if their plugin does not call engine.create or interferes with another plugin's names.