Reintroduce “Random” Sorting in DRep Directory with Pagination Support

[bosko-m]

Bring back the Random sorting option in the DRep Directory, ensuring it works predictably with pagination. Use a deterministic, per-session seed so that paging (next/prev) returns a stable random order during a session, while still allowing users to reshuffle on demand.

Acceptance Criteria

• A Random option appears in the DRep Directory sort dropdown.
• Pagination is stable for a given session seed (no duplicate/reordered items when moving between pages).
• Clicking Shuffle (or equivalent) regenerates the seed and reorders results starting from page 1.
• Random sorting works with existing filters/search and remains performant (no noticeable slowdown).