* test: update sign_in_as system test helper to be more generic
and support fixture users with more than one board
* test: backfill a test for the card "back link"
when coming from a board filter page
* Fix back navigation to filter views from cards
When navigating from a filter view to a card, the back link now shows
the filter's label and navigates back to the filter URL instead of the
card's board.
The turbo-navigation Stimulus controller stores the page title alongside
the referrer URL in sessionStorage. On the card show page, a
referrerBackLink target rewrites the back link's href and label from the
stored values. This is scoped only to the card show page to avoid
navigation loops in multi-level deep pages.
* Add referrer allowlist to prevent stale referrer rewrites
The back link is only rewritten when the stored referrer's path matches
an allowlist of paths passed via prefer_referrer. This prevents stale
referrers from unrelated pages (e.g., settings) from overriding the
card's back link.
* Move back link navigation tests to dedicated system test file
Extract back link tests from smoke_test.rb into their own file since
they test specific JavaScript behavior that needs regression coverage.
Move sign_in_as helper to ApplicationSystemTestCase for reuse.
* Move markdown paste tests to dedicated system test file
Mike Dalessio
248fc5d3e7