Accessibility/semantics pass aligned with React Doctor: role-based spans/divs become real buttons, role=status becomes <output>, modals use native <dialog>, author/peer flags render as <img>, and embed/challenge iframes are sandboxed. Includes review follow-ups: correct button chrome/centering/themed dialog colors and focus rings, the missing aria-label i18n keys (all languages), the Yandex image-search URL, clearer .bso setup steps, a keyboard-accessible image-search dropdown, and removal of the post-edit ('comment edited') display (mod edits unchanged).
Replace sync setState-in-effect with keyed remount and render-derived patterns in app, error-display, topbar-edit-modal, catalog-filters; use useCurrentTime() instead of Date.now() in hot paths; fix conditional hooks, passive scroll listeners, lodash path imports.
Replaced `import _ from 'lodash'` with specific named imports (`capitalize`, `lowerCase`, `debounce`, `startCase`) across 18 files. This reduces bundle size and improves tree-shaking efficiency.
