Documents the current lint state and a strategy for addressing the
remaining issues. 5 errors are all noInvalidUseBeforeDeclaration
that can be fixed by moving useEffect to after function declarations.
The 322 warnings break down into 69 noArrayIndexKey, 113 a11y issues,
18 noUnusedVariables (auto-fixable), 13 useExhaustiveDependencies
(needs useCallback), 30 noNonNullAssertion (manual review), and the
rest are smaller categories.
Tracking via docs/LINT_TODO.md so the runner issue work can proceed
without losing the triage.