Three pre-existing lint issues surfaced during #70's lint check:
- lists/[id]/page.tsx: subtasksMap was `let`, never reassigned -> const
- api/lists/[id]/tasks/route.ts: query was `let`, never reassigned -> const
- Header.tsx: drop unused `Link` import from next/link
Leaves web/ lint at a single remaining error (ThemeToggle
set-state-in-effect), tracked in #90 (needs a design decision:
useSyncExternalStore vs documented eslint-disable).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>