Footnote Stale Duplicate Warning After Delete

Goal

Fix the footnote demo so duplicate-warning state clears when a duplicate set is resolved by deletion, not just by the explicit renumber action.

Scope

• footnote duplicate-state recomputation after node removal
• targeted regression coverage for delete-driven duplicate resolution
• browser verification on the footnote demo

Non-Goals

• changing the duplicate-definition product law
• auto-renumbering footnotes
• broader footnote UX redesign

Current Findings

• The warning UI is derived from api.footnote.isDuplicateDefinition({ path }) and api.footnote.hasDuplicateDefinitions({ identifier }).
• Registry state is supposed to invalidate on insert_node, remove_node, and relevant set_node operations.
• Real bug: deleting the first duplicate definition through the editor can shift the surviving definition to a new path without re-rendering its warning chrome.
• Root cause: useNodePath does not update when sibling edits change this node's path; footnote duplicate UI was reading duplicate state from that stale path.
• Existing tests originally covered duplicate detection and explicit renumber repair, but not stale-path duplicate-state lookup after sibling removal.

Working Plan

• reproduce the stale warning through a targeted test or direct runtime repro
• find the root cause in registry invalidation or duplicate-state lookup
• add regression coverage for the delete path
• implement the durable fix
• verify with targeted tests, browser proof, and lint only

Progress Log

• 2026-04-06: loaded learnings, planning, TDD, debug, task, and react skills
• 2026-04-06: confirmed existing footnote learning and current duplicate-law docs
• 2026-04-06: identified missing coverage for delete-driven duplicate resolution
• 2026-04-06: browser repro proved the package registry was correct but the definition UI stayed stale after sibling removal
• 2026-04-06: fixed the UI to derive current path and duplicate state through useEditorSelector + editor.api.findPath(element) instead of stale useNodePath
• 2026-04-06: made duplicate-warning chrome contentEditable={false} so the warning text and repair button are not editable text surface
• 2026-04-06: verified with targeted bun test, browser-use, and pnpm lint:fix; skipped www build/typecheck by direct user request