* Make membership creation and role updates more explicit in terms of changesets
* Extract invitation accept flow logic and refactor it slightly
* Improve acceptation logic
* Update moduledoc
* Improve SiteLocker API and add typespecs
* Stop naming function not returning a boolean like a predicate
* Refactor rest of invitation actions and safeguard against rogue requests
* Update code docs slightly
* Extend `Billing.check_needs_update/1` tests
* Parametrize selfhost flag and toggle SiteLocker logic on it
* Add tests for newly extracted services
* Add test case and a fix for locking site on grace period ended
* Make invitation controller tests async as there's no more env patching
* Add test cases for self-invites and fix one bug
* Add and refactor tests for rejecting and removing invitations
* Prevent issuing ownership transfer to existing owner
* Improve name of the test
* Improve `Billing.check_needs_to_upgrade/1` return value
* Improve `Billing.SiteLocker.update_sites_for/1` and its tests
* Fix typos
Co-authored-by: hq1 <hq@mtod.org>
* Make invitation removal and rejection resilient to races
---------
Co-authored-by: hq1 <hq@mtod.org>
* Invite existing user to a site
* Add invitation flow for non-existing users
* Accept and reject invitations
* Use invitation flow for existing users
* Locking mechanism for sites
* Authorization for site settings
* Show usage based on site ownership
* Add ability to remove members from a site
* Do not show settings link to viewer roles
* Ability to remove invitations
* Remove `Plausible.Sites.count_for/1`
* Fix tests
* Do not show the trial banner after the trial
* Correct trial emails
* Transfer ownership
* Send invitation email to existing user
* Add invitation email flows
* Add plug for role-based authorization
* Rename AuthorizeStatsPlug -> AuthorizeSiteAccess
* Add email flow for ownership transfer
* Fix URLs in emails
* Fix small copy issues
* Make 'People' its own section in site settings
* Notify user via email if their access has been removed
* Check site lock status when invitation is accepted
* Check lock status when user subscribes
* Make sure only admins and owners can create shared links
* Changelog
* Add LockSites to daily cron
* Clean invitations after 48 hours
* Add notices about expiry
* Add invitation expired page
* Add doc link
