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.

DeepDrftPublic.Client/Pages/ArchiveView.razor.css

@@ -2,11 +2,30 @@
     padding-top: 16px;
 }
 
-.archive-grid {
-    display: grid;
-    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
-    gap: 2rem;
-    margin-top: 1rem;
+.archive-search-row {
+    display: flex;
+    justify-content: flex-start;
+    padding: 0 0 12px 0;
+}
+
+/* archive-search-field rides on MudTextField, whose root is a child Razor component element.
+   Blazor isolation does not stamp the scope attribute there, so ::deep is required. */
+::deep .archive-search-field {
+    max-width: 420px;
+    width: 100%;
+}
+
+.archive-filter-row {
+    display: flex;
+    justify-content: flex-start;
+    flex-wrap: wrap;
+    padding: 0 0 12px 0;
+}
+
+.archive-card-center {
+    display: flex;
+    justify-content: center;
+    width: 100%;
 }
 
 .archive-card-link {
@@ -14,35 +33,51 @@
     color: inherit;
 }
 
-.archive-card {
+.archive-release-card {
     display: flex;
     flex-direction: column;
-    align-items: center;
-    text-align: center;
-    gap: 0.75rem;
-    padding: 2.5rem 1.5rem;
-    border: 1px solid var(--mud-palette-lines-default);
+    width: 200px;
+    cursor: pointer;
     border-radius: 8px;
-    background-color: var(--mud-palette-surface);
-    transition: transform 120ms ease, box-shadow 120ms ease;
+    overflow: hidden;
+    transition: transform 120ms ease;
 }
 
-.archive-card:hover {
+.archive-release-card:hover {
     transform: translateY(-4px);
-    box-shadow: 0 8px 28px color-mix(in srgb, var(--mud-palette-text-secondary) 18%, transparent);
 }
 
-/* archive-card-icon rides on MudIcon (child Razor component); ::deep pierces its output. */
-::deep .archive-card-icon {
-    font-size: 56px;
-    color: var(--mud-palette-primary);
+.archive-release-cover {
+    width: 200px;
+    height: 200px;
+    background-size: cover;
+    background-position: center;
+    background-repeat: no-repeat;
 }
 
-/* archive-card-title / archive-card-blurb ride on MudText (child Razor component). */
-::deep .archive-card-title {
+.archive-release-cover--fallback {
+    background-color: var(--mud-palette-dark, #1a2238);
+}
+
+.archive-release-body {
+    padding: 8px 4px 0 4px;
+    display: flex;
+    flex-direction: column;
+    gap: 2px;
+}
+
+/* archive-release-title / archive-release-artist ride on MudText (child Razor component); ::deep
+   pierces into its output since Blazor isolation does not scope-stamp child component roots. */
+::deep .archive-release-title {
     font-weight: 600;
 }
 
-::deep .archive-card-blurb {
+::deep .archive-release-artist {
     opacity: 0.7;
 }
+
+.archive-empty {
+    display: flex;
+    justify-content: center;
+    padding: 48px 0;
+}