Task: Close the entity-shell gaps a second entity would inherit

Close the Tier 1, Tier 2 and Tier 3 findings in gaps.org so the second entity does not inherit them: a get-one route so a deep link resolves past the first page, a read-only historical mode so opening a version opens that version, sorting on the underlying value, remembered column visibility and order, keyboard navigation, validation on blur, the unsaved-changes prompt, the searchable foreign-key select, and a negative-path verification harness. gaps.org is updated to say what closed and what did not.

• Each Tier 1, 2 and 3 finding is met or explicitly re-scoped with a reason recorded in gaps.org.
• A deep link to a record beyond the first page resolves.
• Opening a historical version shows that version, read-only.
• The verification script exercises a rejected or empty case as well as a good one.
• Sorting uses the underlying value, not the displayed string.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

Manual QA scenarios (scaffolded via compass add test_scenario) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

Superseded on 2026-09-23. This task closes gaps that a second entity would inherit from the shell, and no entity goes through the shell any more. The shell and gaps.org are both gone, so there is nothing left to close.