~x-ai/grok-latest → A (3:1)

Commit A redesigns recent-votes storage (Deque→List/Vec, write-time trim removed in favor of read-time cap, schema bump + regression test), a lasting core-data-model improvement; B only deletes a leftover monolithic forum.rs so the already-split forum/ modules become unambiguous, which is necessary cleanup but mostly mechanical deduplication.