improve Frontend

src/ClaudeDo.Data/Configuration/TaskEntityConfiguration.cs

@@ -51,6 +51,7 @@ public class TaskEntityConfiguration : IEntityTypeConfiguration<TaskEntity>
         builder.Property(t => t.IsStarred).HasColumnName("is_starred").HasDefaultValue(false);
         builder.Property(t => t.IsMyDay).HasColumnName("is_my_day").HasDefaultValue(false);
         builder.Property(t => t.Notes).HasColumnName("notes");
+        builder.Property(t => t.SortOrder).HasColumnName("sort_order").IsRequired().HasDefaultValue(0);
 
         builder.HasOne(t => t.List)
             .WithMany(l => l.Tasks)
@@ -74,5 +75,6 @@ public class TaskEntityConfiguration : IEntityTypeConfiguration<TaskEntity>
 
         builder.HasIndex(t => t.ListId).HasDatabaseName("idx_tasks_list_id");
         builder.HasIndex(t => t.Status).HasDatabaseName("idx_tasks_status");
+        builder.HasIndex(t => new { t.ListId, t.SortOrder }).HasDatabaseName("idx_tasks_list_sort");
     }
 }

src/ClaudeDo.Data/Migrations/20260422120000_AddTaskSortOrder.cs

@@ -0,0 +1,48 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ClaudeDo.Data.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddTaskSortOrder : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<int>(
+                name: "sort_order",
+                table: "tasks",
+                type: "INTEGER",
+                nullable: false,
+                defaultValue: 0);
+
+            // Backfill existing rows with a per-list dense order (0..N-1) by creation time
+            // so today's UI order is preserved after the migration.
+            migrationBuilder.Sql("""
+                WITH ordered AS (
+                    SELECT id, (row_number() OVER (PARTITION BY list_id ORDER BY created_at) - 1) AS rn
+                    FROM tasks
+                )
+                UPDATE tasks SET sort_order = (SELECT rn FROM ordered WHERE ordered.id = tasks.id);
+                """);
+
+            migrationBuilder.CreateIndex(
+                name: "idx_tasks_list_sort",
+                table: "tasks",
+                columns: new[] { "list_id", "sort_order" });
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "idx_tasks_list_sort",
+                table: "tasks");
+
+            migrationBuilder.DropColumn(
+                name: "sort_order",
+                table: "tasks");
+        }
+    }
+}

src/ClaudeDo.Data/Migrations/ClaudeDoDbContextModelSnapshot.cs

@@ -281,6 +281,12 @@ namespace ClaudeDo.Data.Migrations
                         .HasColumnType("TEXT")
                         .HasColumnName("scheduled_for");
 
+                    b.Property<int>("SortOrder")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("INTEGER")
+                        .HasDefaultValue(0)
+                        .HasColumnName("sort_order");
+
                     b.Property<DateTime?>("StartedAt")
                         .HasColumnType("TEXT")
                         .HasColumnName("started_at");
@@ -307,6 +313,9 @@ namespace ClaudeDo.Data.Migrations
                     b.HasIndex("Status")
                         .HasDatabaseName("idx_tasks_status");
 
+                    b.HasIndex("ListId", "SortOrder")
+                        .HasDatabaseName("idx_tasks_list_sort");
+
                     b.ToTable("tasks", (string)null);
                 });
 

src/ClaudeDo.Data/Models/TaskEntity.cs

@@ -29,6 +29,7 @@ public sealed class TaskEntity
     public bool IsStarred { get; set; }
     public bool IsMyDay { get; set; }
     public string? Notes { get; set; }
+    public int SortOrder { get; set; }
 
     // Navigation properties
     public ListEntity List { get; set; } = null!;

src/ClaudeDo.Data/Repositories/TaskRepository.cs

@@ -14,6 +14,13 @@ public sealed class TaskRepository
 
     public async Task AddAsync(TaskEntity entity, CancellationToken ct = default)
     {
+        // Append at bottom of the list by default: SortOrder = max(listId) + 1.
+        var maxSort = await _context.Tasks
+            .Where(t => t.ListId == entity.ListId)
+            .Select(t => (int?)t.SortOrder)
+            .MaxAsync(ct);
+        entity.SortOrder = (maxSort ?? -1) + 1;
+
         _context.Tasks.Add(entity);
         await _context.SaveChangesAsync(ct);
     }
@@ -38,10 +45,32 @@ public sealed class TaskRepository
     {
         return await _context.Tasks
             .Where(t => t.ListId == listId)
-            .OrderBy(t => t.CreatedAt)
+            .OrderBy(t => t.SortOrder).ThenBy(t => t.CreatedAt)
             .ToListAsync(ct);
     }
 
+    /// <summary>
+    /// Renumbers tasks in a list to 0..N-1 according to <paramref name="orderedTaskIds"/>.
+    /// Ids not belonging to the list are ignored; ids missing from the list are untouched.
+    /// </summary>
+    public async Task ReorderAsync(string listId, IReadOnlyList<string> orderedTaskIds, CancellationToken ct = default)
+    {
+        if (orderedTaskIds.Count == 0) return;
+
+        var idSet = orderedTaskIds.ToHashSet();
+        var tasks = await _context.Tasks
+            .Where(t => t.ListId == listId && idSet.Contains(t.Id))
+            .ToListAsync(ct);
+
+        for (int i = 0; i < orderedTaskIds.Count; i++)
+        {
+            var task = tasks.FirstOrDefault(t => t.Id == orderedTaskIds[i]);
+            if (task is not null) task.SortOrder = i;
+        }
+
+        await _context.SaveChangesAsync(ct);
+    }
+
     // Kept for backwards-compatibility with callers using the old name.
     public Task<List<TaskEntity>> GetByListAsync(string listId, CancellationToken ct = default)
         => GetByListIdAsync(listId, ct);
@@ -205,7 +234,7 @@ public sealed class TaskRepository
                           WHERE lt.list_id = t.list_id AND tg.name = 'agent'
                       )
                   )
-                ORDER BY t.created_at ASC
+                ORDER BY t.sort_order ASC, t.created_at ASC
                 LIMIT 1
             )
             RETURNING *