Support inline event attributes in the main tracking script #105

What

Support the documented data-simple-event clicks, form submissions, attribute metadata, and optional confirmed 404 events in the main tracking script. Currently these require a separate inline-events helper, while v12's automatic-events script skips tagged links.

Why

Customers should be able to use these attributes with one small tracking script, without duplicate events or changes to their site's navigation, form validation, or submission behavior.

Notes

Implement against v12 (PR #40). Preserve installations that still include the separate helper, and keep the added compressed size small.