feat(public-nav): slim appbar to ARCHIVE + inline CUTS/SESSIONS/MIXES, drop GENRES and Tracks (8.I)

Desktop flattens the ARCHIVE popover into inline appbar links above the medium
breakpoint; mobile keeps the indented sub-list under ARCHIVE. GENRES and /tracks
removed from nav only — routes (GenresView, TracksView) remain reachable by URL.
Retires the now-dead desktop hover-popover and its 8.J collapse-state machinery
(mobile drawer still dismisses on click).

DeepDrftPublic.Client/Layout/Pages.cs

@@ -19,6 +19,11 @@ public class PageRoute
 
 public static class Pages
 {
+    // ARCHIVE (→ the release-cardinal /archive browser) carries the three medium modes as Children.
+    // Above the medium breakpoint the desktop nav flattens them into inline appbar links beside
+    // ARCHIVE (no popover); below the breakpoint the mobile hamburger renders them as an indented
+    // sub-list under ARCHIVE. /tracks and /genres are intentionally absent from the nav (8.I) —
+    // their routes (TracksView, GenresView) remain reachable by direct URL.
     public static readonly List<PageRoute> MenuPages =
     [
         new()
@@ -31,8 +36,6 @@ public static class Pages
                 new() { Name = "Mixes",    Route = "/mixes",    Icon = Icons.Material.Filled.GraphicEq },
             ],
         },
-        new() { Name = "Tracks", Route = "/tracks", Icon = Icons.Material.Filled.MusicNote },
-        new() { Name = "Genres", Route = "/genres", Icon = Icons.Material.Filled.Category },
     ];
 
     public static readonly List<PageRoute> AllPages =