Docs: document plugin registry generation step for create-sonicjs users

[lane711]

Problem

Users who scaffold a new project via npx create-sonicjs my-app are not aware that plugins won't be picked up unless the plugin registry is generated or routes are manually mounted.

This came up in Discord — a user couldn't get plugins working because neither the plugin development docs nor the default template mention the required setup step.

What's missing

Plugins require one of the following to work:

1. Generate the plugin registry via generate-plugin-registry.mjs, or
2. Manually mount plugin routes in src/index.ts:

// Mount plugin routes
if (contactFormPlugin.routes) {
  for (const route of contactFormPlugin.routes) {
    app.route(route.path, route.handler)
  }
}

// Mount core app last
app.route('/', coreApp)

Suggested fix

• Add a clear callout in the plugin development docs explaining the registry generation step
• Update the create-sonicjs template or its README to mention this requirement
• Consider adding a note in the getting started guide for plugin consumers

Source

Discord community feedback.