Submit native non-Purchase events using a signed public surface context

Separate from first-party analytics ingestion. The token binds the current page or store, configured destinations, trigger selections and their revision. If the configuration changes, intake returns tracking_configuration_changed (409) and the page must reload; token renewal preserves the original mappings. Purchase and arbitrary Google targets are rejected. Batches are limited to 20 events and 32 KiB of event data, with per-business and per-IP limits. Tokens expire after seven days; renewal requires a valid original signature no older than 30 days and current assignments. Acceptance is not ingestion or attribution confirmation.