feat: replace /archive with release-cardinal searchable browser (Phase 9 §8.H)

Retire the three-card overview for a search + medium + genre browser over all
releases. Adds q/genre filter params to the api/release paged read path,
mirroring the existing api/track/page TrackFilter pattern.

DeepDrftData/ReleaseManager.cs

@@ -42,7 +42,7 @@ public class ReleaseManager : IReleaseService
 
     public async Task<ResultContainer<PagedResult<ReleaseDto>>> GetPagedAsync(
         int page, int pageSize, string? sortColumn, bool sortDescending,
-        ReleaseMedium? medium, CancellationToken cancellationToken = default)
+        ReleaseMedium? medium, ReleaseFilter? filter = null, CancellationToken cancellationToken = default)
     {
         try
         {
@@ -54,7 +54,9 @@ public class ReleaseManager : IReleaseService
                 IsDescending = sortDescending,
             };
 
-            var entityPage = await _repository.GetPagedByMediumAsync(parameters, medium, cancellationToken);
+            // Collapse an all-null filter to null so the repository skips the predicate block entirely.
+            var effectiveFilter = filter is { IsEmpty: false } ? filter : null;
+            var entityPage = await _repository.GetPagedByMediumAsync(parameters, medium, effectiveFilter, cancellationToken);
 
             var releaseIds = entityPage.Items.Select(r => r.Id).ToList();
             var counts = await _repository.GetTrackCountsByReleaseIdsAsync(releaseIds, cancellationToken);