b5de3c2b

By: Michael Lynch <git@mtlynch.io>

Allow per-item decisions during bulk adds

Prompt for each duplicate during stored-list applies and support Yes, No,
Yes to All, and No to All choices. Preserve non-duplicate additions and cart
state while applying the selected merge decisions.

Add end-to-end coverage for two distinct existing cart items and all four
bulk choices.

Testing: ./dev-scripts/run-e2e-tests
Testing: ./dev-scripts/build-all-flake-targets