Task 1 leaves 4 tests and Task 2 adds 7, so the running total is 11 rather than 12, and the same off-by-one carried into Tasks 3, 4 and the completion criteria. Caught by the Task 2 implementer, which flagged the mismatch rather than inventing a test to reach the stated number.
Nine tasks, each ending in something independently testable, in an order where every task leaves both screens working. The dimensions are built and unit-tested first, the shell after them, and the two screens are wired last — so the old components stay in place until the thing replacing them is proven.
The two behaviour changes the design accepted are each covered twice: a unit test on the chips that produce them, and an end-to-end assertion on what a person sees. The admin tally reading three for three statuses, and a non-default availability producing a removable chip.
Task 8 carries the deletions, deliberately last. Removing `activeFilterCount` and `hasActiveFilters` turns every remaining caller into a compile error, which is the cheapest way to find them.
Two defects found reviewing the plan against the code rather than against itself: the test fixture omitted `Category.item_count` and would not have compiled, and Task 9 added a page object method that nothing used — `chooseAvailability` and `filterChip` already exist.
The plan also records what must not be read as a regression. Two assertions in the storefront specs fail on every branch because the unpaginated grid cannot render 1,600+ development rows inside Playwright's default timeout, which is #186 and predates this work.
Refs #188
Four tasks, each ending in an independently testable deliverable: the backend endpoint with its own rate limiter, the boundary and fallback components, the three mount points with end-to-end coverage, and the production-gate verification.
Refs #62
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>