Remove onReady callback from plugin

The onReady callback is no longer needed since the plugin no longer
schedules initial processing jobs during initialization.

src/plugin.ts

@@ -107,10 +107,6 @@ export const mailingPlugin = (pluginConfig: MailingPluginConfig) => (config: Con
       } as MailingContext
 
 
-      // Call onReady callback if provided
-      if (pluginConfig.onReady) {
-        await pluginConfig.onReady(payload)
-      }
 
       if (pluginConfig.initOrder !== 'after' && config.onInit) {
         await config.onInit(payload)

src/types/index.ts

@@ -76,7 +76,6 @@ export interface MailingPluginConfig {
   templateEngine?: TemplateEngine
   richTextEditor?: RichTextField['editor']
   beforeSend?: BeforeSendHook
-  onReady?: (payload: any) => Promise<void>
   initOrder?: 'before' | 'after'
 }