feat(audit-log): filter from an entry's detail, name members, show where it came from - #2423

🟢 Confidence 10/10 · safe to merge. Each new behavior (pivots, reveal, member names, origin) has a scene test, and the entry-link pivot fix is pinned by a URL assertion.
_{no findings · tests covered · risk medium}

Adds Filter pivots from an entry's detail, member names for unnamed actors and membership changes, an Origin section, and a per-entry link that expands and scrolls to its entry; a filter change now also drops ?entry=. Safe to merge.

Fixed since the last review

• ✅ F5 · Pivot from a shared entry link keeps that link's one-minute window

_{7fbd842 · Reply "won't fix" to dismiss a finding, or mention @maple-review-bot to ask about one.}