Phase 9 Wave 4: ARCHIVE nav + Cuts/Sessions/Mixes pages + MixWaveformVisualizer

Replaces flat RELEASES/SESSIONS/MIXES nav with ARCHIVE dropdown (PageRoute.Children,
one-level cap, dual-role node). Adds /archive overview, /cuts (AlbumsView + medium
filter; /albums redirects), /sessions + /sessions/{id} (hero-dominant), /mixes +
/mixes/{id} (MixWaveformVisualizer full-page background). Extracts ReleaseDetailScaffold
from TrackDetail (invariant trio). PersistentComponentState bridge on all new pages.
Click-to-seek seam designed on MixWaveformVisualizer (inert until wired).

DeepDrftPublic.Client/Services/ReleaseClientDataService.cs

@@ -0,0 +1,35 @@
+using DeepDrftModels.DTOs;
+using DeepDrftPublic.Client.Clients;
+using Models.Common;
+using NetBlocks.Models;
+
+namespace DeepDrftPublic.Client.Services;
+
+/// <summary>
+/// <see cref="IReleaseDataService"/> backed by <see cref="ReleaseClient"/> (HTTP to the
+/// <c>DeepDrft.API</c> backend). Used on both the SSR prerender and WASM interactive passes —
+/// the release read surface is HTTP-only, so there is no separate in-process implementation.
+/// </summary>
+public class ReleaseClientDataService : IReleaseDataService
+{
+    private readonly ReleaseClient _releaseClient;
+
+    public ReleaseClientDataService(ReleaseClient releaseClient)
+    {
+        _releaseClient = releaseClient;
+    }
+
+    public Task<ApiResult<PagedResult<ReleaseDto>>> GetPaged(
+        string? medium,
+        int page,
+        int pageSize,
+        string? sortColumn = null,
+        bool sortDescending = false)
+        => _releaseClient.GetPaged(medium, page, pageSize, sortColumn, sortDescending);
+
+    public Task<ApiResult<ReleaseDto>> GetById(long id)
+        => _releaseClient.GetById(id);
+
+    public Task<ApiResult<WaveformProfileDto?>> GetMixWaveform(long id)
+        => _releaseClient.GetMixWaveform(id);
+}