Snapshot v0.2.4 — overdue release

Publishes the work accumulated on main since 0.2.3: SSR/hydration fixes, community hooks, notification hooks (useMarkAllNotificationsSeen, useDismissNotification), useUnlockThread, rich-input link insertion, cookie-refresh and auth redirect hardening, theme persistence.

Consumers installing from the registry were missing hooks that already existed in the source tree — sgforum's typecheck failed against 0.2.3 for exactly this reason.

Also documents PaginatedResponse, which the docs-coverage release gate required.