refactor: tighten the home typography and card craft

The playlist cards were showing "No description was pr…" because the API
stored that English sentence whenever a playlist was created without a
description. Descriptions are optional now and the old rows are cleared.

Section headings drop to 18/20px so they stop competing with the content,
and the space moved from inside the sections to between them.

The three media cards repeated the same anchor, art class and label
block, so they share a MediaCard that also carries the hover lift the
track tiles already had.

backend/Musify.Api/DataTransferObjects/PlayLists/CreatePlayListRequest.cs

@@ -2,5 +2,5 @@ namespace Musify.Api.DataTransferObjects.PlayLists;
 
 public record CreatePlayListRequest(
     string Name,
-    string Description,
+    string? Description,
     Guid? PictureIntentId);

backend/Musify.Api/Endpoints/PlayListEndpoints.cs

@@ -181,12 +181,8 @@ public static class PlayListEndpoints
         CreatePlayListRequest request,
         CancellationToken cancellationToken)
     {
-        var description = string.IsNullOrWhiteSpace(request.Description)
-            ? "No description was provided."
-            : request.Description;
-
         var result = await mediator.Send(
-            new CreatePlayListCommand(currentUser.RequiredId, request.Name, description, request.PictureIntentId),
+            new CreatePlayListCommand(currentUser.RequiredId, request.Name, request.Description, request.PictureIntentId),
             cancellationToken);
 
         return result.ToCreatedResult(playList => $"/playlists/{playList.Id}");

backend/Musify.Application/PlayLists/CreatePlayList.cs

@@ -16,7 +16,7 @@ namespace Musify.Application.PlayLists
     public record CreatePlayListCommand(
         long UserId,
         string Name,
-        string Description,
+        string? Description,
         Guid? PictureIntentId)
         : ICommand<ErrorOr<PlayListApplicationResponse>>;
 
@@ -58,7 +58,7 @@ namespace Musify.Application.PlayLists
                 UserId = request.UserId,
                 Name = request.Name,
                 NormalizedName = request.Name.Trim().ToUpperInvariant(),
-                Description = request.Description,
+                Description = string.IsNullOrWhiteSpace(request.Description) ? null : request.Description.Trim(),
                 Pictures = pictureIntent == null ? null
                     : new PlayListPictures { OriginalName = pictureIntent.ObjectName }
             };

backend/Musify.Domain/Entities/PlayList.cs

@@ -1,4 +1,4 @@
-using System.ComponentModel.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
 using System.ComponentModel.DataAnnotations.Schema;
 
 using Musify.Domain.Abstractions;
@@ -24,7 +24,6 @@ namespace Musify.Domain.Entities
         [MaxLength(50)]
         public required string NormalizedName { get; set; }
 
-        [Required]
         [MaxLength(256)]
         public string? Description { get; set; }
 

backend/Musify.Infrastructure/Persistence/Migrations/20260721190735_MakePlayListDescriptionOptional.cs

@@ -0,0 +1,46 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Musify.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class MakePlayListDescriptionOptional : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterColumn<string>(
+                name: "Description",
+                table: "PlayLists",
+                type: "character varying(256)",
+                maxLength: 256,
+                nullable: true,
+                oldClrType: typeof(string),
+                oldType: "character varying(256)",
+                oldMaxLength: 256);
+
+            migrationBuilder.Sql(
+                """
+                UPDATE "PlayLists" SET "Description" = NULL
+                WHERE "Description" = 'No description was provided.';
+                """);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AlterColumn<string>(
+                name: "Description",
+                table: "PlayLists",
+                type: "character varying(256)",
+                maxLength: 256,
+                nullable: false,
+                defaultValue: "",
+                oldClrType: typeof(string),
+                oldType: "character varying(256)",
+                oldMaxLength: 256,
+                oldNullable: true);
+        }
+    }
+}

backend/Musify.Infrastructure/Persistence/Migrations/DatabaseModelSnapshot.cs

@@ -409,7 +409,6 @@ namespace Musify.Infrastructure.Persistence.Migrations
                         .HasColumnType("timestamp with time zone");
 
                     b.Property<string>("Description")
-                        .IsRequired()
                         .HasMaxLength(256)
                         .HasColumnType("character varying(256)");