ROADMAP's U7 row names four components. Three of them -- a sticky rail,
filters, and grid keyboard -- are already ratified there and are implemented
here. The fourth, replacing directory sections with filename-derived groups, is
a scope DEPARTURE the operator has not ruled on and is deliberately not built;
test_no_group_rail_is_shipped_yet fails the moment somebody builds it anyway,
so it cannot arrive by accident while he is away.
Filters are links carrying a query parameter, resolved server-side, so the
gallery keeps working with JavaScript off -- U3 already cost the verbatim path
its no-JS operation and said so, and the gallery is the surface the operator
actually reviews on. An unknown filter falls back to `all` rather than indexing
a dict by a value that arrives from an operator-editable URL.
`unanswered` means HAS AN OPEN PICK, the U4 hold predicate that already exists.
The other reading is a real and different question and stays open on the
contract rather than being guessed at.
Filtering is a VIEW and never reorders. The grid renders `sorted(rel)` with
non-matching items removed, so "the third one" means the same thing with a
filter on as with it off, and the zoom ring is untouched by any filter -- a
ring that changed with the grid would make `next` depend on how the operator
arrived, which is the misfiled-judgment failure invariant 6 exists for.
⚠ The first version of that invariant's test was VACUOUS and the mutation run
caught it: it compared each filtered view against the unfiltered RESPONSE, so a
reversing mutation reversed both sides and it stayed green under the exact
change it forbade. Rewritten against an independent truth -- U1 INV-3 says the
order IS sorted(rel) -- and re-verified RED. Written an hour after the entry
describing this exact failure class, which is worth recording.
611 -> 623 tests.
Not approved and not implemented. Frontmatter status says so, the body says so
twice, and the one scope-direction call in it is named as the operator's.
ROADMAP's U7 row is sections, rail, filters, grid keyboard. The measurement
recorded in persistent-memory.d/2026-09-22-u7-remeasured-before-scoping.md
kills the first component -- zero of eleven gallery booths have a subdirectory,
and the only two booths that do are reports -- and supplies a replacement:
stripping a trailing digit-run from the filename stem yields 5 to 16 sensible
groups on four of the five large galleries.
The degenerate fifth is carried as a first-class case rather than an edge: one
group must render NO rail, because a navigation affordance that cannot navigate
is worse than none.
Closes ROADMAP's outstanding U7 ordering question: groups order by the position
of their first member in sorted(rel), so the rail reads in the same direction
as the grid. Grouping and filtering are views and never reorder -- INV-2 exists
because sorting by (group, rel) looks right and silently changes what 'the
third one' means, which is the misfiled-judgment failure invariant 6 was
written for.
Blast radius checked before writing: Item gains one field beside the existing
section, build_gallery carries it, and image_chain is explicitly unchanged.
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