Shoji 1.5.0

Campaign tag of the visit for Digistore24 order forms.

Added

• Option campaignParam names the request parameter with the campaign tag, for example 'cam' (utm_campaign wins). A Digistore24 order form rendered on such a page takes the tag as ds24tr, the vendor's tracking key, in its signed address, unless the form has an affiliate (aff) or a ds24tr already; an own cam is dropped, because Digistore24 reads cam only as the campaign of an affiliate.
• A page address with aff= is a partner's visit: nothing is carried on, so the partner's tag never reaches the vendor's purchase data as the site's own.
• Without a visit tag a pasted cam without aff becomes ds24tr the same way. A pasted address may now carry ds24tr.
• Providers get the optional field campaign (a closure); Embed::campaign($kirby) returns the tag of the request.

Nothing loads earlier; the redirect targets are unchanged apart from the parameter. Full notes: CHANGELOG.md.