Part of #18610.
Our intent is to move `definePlugin`, `defineRule`, and `eslintCompatPlugin` to a separate package `@oxlint/plugins` (plural to avoid confusion with naming convention for plugins `oxlint-plugin-xxx`).
So rename the current entry point which exports these functions from `oxlint/plugin` to `oxlint/plugins` (plural).
This is technically breaking (only for types), but custom plugins are experimental.
The ruletester/defineRule/definePlugin are re-exported but with a `@deprecated` tag which I think is a good enough trade off
I want to avoid users bringing in a ton of custom plugin code when doing `import { defineConfig } from 'oxlint'`
Fixes#15631.
#16930 implemented options validation against `rule.meta.schema`, for the purpose of supporting default options added by schema. But it didn't actually do anything if validation failed.
Implement validation of options against schema, and pass any errors back to Rust to print.
overlookmotel