Replace eslint.config.js with eslint.config.ts and split rules into modular
eslint/ files (react, sonar, style, tests, stories, imports). Add custom
local/padding-react-hooks rule that enforces padding around React hook calls
(no blank lines between hooks, required before/after const/expression). Add
@types/eslint-plugin-jsx-a11y and @typescript-eslint/utils as dev deps.
