Implement server-side searchable user filtering for usage records, including backend search parameters and a shared frontend selector with loading, empty, and pinned-selected states.
Fix announcement deletion by cascading announcement read rows through a Postgres migration and defensive repository cleanup across supported backends.
Wire admin system purge and cleanup endpoints to real data deletion/maintenance flows, improve DataManagement messages, rebuild stats after stats purge, and add runtime OAuth token refresh maintenance when enabled.
Verified with rust-ci equivalent checks: cargo fmt, split clippy, split cargo tests, SQLite/Postgres/MySQL smoke tests, plus frontend npm ci, build, pages build, type-check, and targeted usage selector tests.
elky