Centralize review reaction state transitions

[jenul-ferdinand]

What

Move review reaction optimistic updates, server mutation, and rollback behaviour from Review Card into the frontend Review module.

Why

Review Card changes current-user reaction sets, sends the request, and restores state on failure. That lifecycle belongs with the other review transitions.

Area

• frontend

Parent tracking issue

• [Parent] Consolidate frontend review lifecycle orchestration #258 Consolidate frontend review lifecycle orchestration

Notes or constraints

• Depend on Centralize review create, edit, and delete lifecycle #261.
• Preserve visible reaction counts and user feedback.
• Test like, unlike, dislike, undislike, reaction switching, request failure, and rollback.

Done when

• Review Card renders reaction state without owning optimistic-update logic.
• The Review module owns reaction transitions and rollback.