WordPress plugin: lifecycle (activate / deactivate / uninstall)

The three events that frame a plugin's existence on a site. Each has a different scope, different runtime context, and different non-negotiable rules. Get the contract wrong and you ship plugins that:

• Activate "successfully" but leave the site in a broken state.
• Leave behind cron events that fire forever after deactivation.
• Leave 50 orphan options + 100k orphan meta rows after uninstall.

This skill assumes the plugin already has a clean bootstrap (see wp-plugin-bootstrap). It covers ONLY what happens at the three lifecycle boundaries.

For update-time migrations after plugin files are replaced, use wp-plugin-update-migrations. Activation does not fire on ordinary plugin update.

When to use this skill

Trigger when ANY of the following is true: