A refused save on the target edit page now shows the edit form again,
with the reason above it and every value submitted, instead of a bare
text page; the status codes are unchanged. The webhook edit page keeps
the submitted name, description and retention the same way, while the
page still reports the stored retention.
Target edits are validated by setTargetFromForm, which newTarget now
uses too, so the add and edit forms accept and refuse the same things.
An empty max_retries keeps the target's own count.
The browser test also saves both edit pages with refused values. Its
seeding and its table of target types move into helpers, leaving the
test function a plain list of check calls.
Model: opus-5-5
The targets section of the webhook page showed its add form open with every field, a URL included for types that use none. It now lists only its targets until "+ Add" is clicked; "+ Add" shows a choice of target type with Next and Cancel on one row, and Next shows the name and only that type's fields. The database and log types show no URL field and the server stores none for them; the slack form gains its retry field. A refused target brings the page back with the form open on its type, the values entered and the reason, and Cancel empties it. An encoding failure stays a logged 500. Target validation returns its message, so the new-webhook page can reuse it.
Model: opus-5-5