feat(fe): optimize error handling, state consistency, and WS feedback

- Add global SWR config with exponential backoff retry (swr-config.ts)
- Add ErrorBoundary component for React crash recovery (error-boundary.tsx)
- Standardize ErrorState onRetry on all 6 dashboard views (dashboard, media,
  messages, moderation, recordings, voice)
- Fix useAction: expose resetError + onError callback
- Refactor useSpeakers to SWR-backed state (was local useState) for
  consistent cache/revalidate semantics with other hooks
- Remove polling in useReview (15s refreshInterval); replace with
  useReviewWsSync subscribing to WS moderation_action events
- Extract hashUserId to lib/hash.ts (de-dup with ambient-canvas)
- WS context: add reconnect/error toast feedback via onStatusChange
- WS connection: expose reconnectAttemptCount getter

All typecheck + lint clean, Next 16 build passes.

services/frontend/src/components/shared/index.ts

@@ -2,6 +2,7 @@ export { GuildChannelPicker } from "./guild-picker";
 export { MarkdownLite } from "./markdown";
 export { PageTransition } from "./page-transition";
 export { MetricTile, SectionHeader } from "./section";
+export { ErrorBoundary } from "./error-boundary";
 export {
   EmptyState,
   ErrorState,