Fix task and shift self-assignment features

backend/WorkClub.Application/Shifts/DTOs/ShiftDetailDto.cs

@@ -12,7 +12,8 @@ public record ShiftDetailDto(
     Guid ClubId,
     Guid CreatedById,
     DateTimeOffset CreatedAt,
-    DateTimeOffset UpdatedAt
+    DateTimeOffset UpdatedAt,
+    bool IsSignedUp
 );
 
 public record ShiftSignupDto(

backend/WorkClub.Application/Shifts/DTOs/ShiftListDto.cs

@@ -13,5 +13,6 @@ public record ShiftListItemDto(
     DateTimeOffset StartTime,
     DateTimeOffset EndTime,
     int Capacity,
-    int CurrentSignups
+    int CurrentSignups,
+    bool IsSignedUp
 );

backend/WorkClub.Application/Tasks/DTOs/TaskDetailDto.cs

@@ -10,5 +10,6 @@ public record TaskDetailDto(
     Guid ClubId,
     DateTimeOffset? DueDate,
     DateTimeOffset CreatedAt,
-    DateTimeOffset UpdatedAt
+    DateTimeOffset UpdatedAt,
+    bool IsAssignedToMe
 );

backend/WorkClub.Application/Tasks/DTOs/TaskListDto.cs

@@ -12,5 +12,6 @@ public record TaskListItemDto(
     string Title,
     string Status,
     Guid? AssigneeId,
-    DateTimeOffset CreatedAt
+    DateTimeOffset CreatedAt,
+    bool IsAssignedToMe
 );