Add filter to /admin/audit-log admin page, modeled on Mars /administrar/logs filter

SIZE-FIRST (Elazar spend-watch): if more than a small lift, confirm with Elazar before building. Add a filter UI to venus admin audit-log page (https://cmfpost-evolutiva.pensanta.com/admin/audit-log), modeled on Mars's /administrar/logs filter impl. Mars source readable on this host (bin-venus holds all app code) — coder reads Mars's logs-page filter as the pattern. Separate from the appEvents telemetry standardization (VENUS-188). Class-S candidate: single admin surface, reversible, security-inert.