feat(privacy): add user privacy settings and account deletion system

Add privacy settings allowing users to control visibility of their followers, following, posts, and favorites lists with three visibility levels: everyone, following, and self. Also implement account deletion workflow with 30-day cooldown period.

- Add PrivacySettings model with visibility levels
- Add DTOs for privacy settings and account deletion
- Add repository methods for privacy settings and deletion
- Add service methods to check visibility permissions
- Add handlers for get/update privacy settings and account deletion
- Add new routes for privacy settings and account management
- Add account cleanup service for hard-deleting expired accounts
- Modify login to cancel deletion when user logs in

BREAKING CHANGE: Users with pending_deletion status can no longer log in; logging in now automatically cancels deletion requests.

internal/dto/user_converter.go

@@ -40,22 +40,35 @@ func ConvertUserToSelfResponse(user *model.User, postsCount int) *UserSelfRespon
 		return nil
 	}
 	return &UserSelfResponse{
-		ID:             user.ID,
-		Username:       user.Username,
-		Nickname:       user.Nickname,
-		Email:          user.Email,
-		Phone:          user.Phone,
-		EmailVerified:  user.EmailVerified,
-		Avatar:         getAvatarOrDefault(user),
-		CoverURL:       user.CoverURL,
-		Bio:            user.Bio,
-		Website:        user.Website,
-		Location:       user.Location,
-		PostsCount:     postsCount,
-		FollowersCount: user.FollowersCount,
-		FollowingCount: user.FollowingCount,
-		IsVerified:     user.IsVerified,
-		CreatedAt:      FormatTime(user.CreatedAt),
+		ID:              user.ID,
+		Username:        user.Username,
+		Nickname:        user.Nickname,
+		Email:           user.Email,
+		Phone:           user.Phone,
+		EmailVerified:   user.EmailVerified,
+		Avatar:          getAvatarOrDefault(user),
+		CoverURL:        user.CoverURL,
+		Bio:             user.Bio,
+		Website:         user.Website,
+		Location:        user.Location,
+		PostsCount:      postsCount,
+		FollowersCount:  user.FollowersCount,
+		FollowingCount:  user.FollowingCount,
+		IsVerified:      user.IsVerified,
+		CreatedAt:       FormatTime(user.CreatedAt),
+		PrivacySettings: convertPrivacySettingsToResponse(&user.PrivacySettings),
+	}
+}
+
+func convertPrivacySettingsToResponse(ps *model.PrivacySettings) *PrivacySettingsResponse {
+	if ps == nil {
+		return nil
+	}
+	return &PrivacySettingsResponse{
+		FollowersVisibility: string(ps.FollowersVisibility),
+		FollowingVisibility: string(ps.FollowingVisibility),
+		PostsVisibility:     string(ps.PostsVisibility),
+		FavoritesVisibility: string(ps.FavoritesVisibility),
 	}
 }
 
@@ -159,21 +172,22 @@ func ConvertUserToDetailResponse(user *model.User) *UserDetailResponse {
 		return nil
 	}
 	return &UserDetailResponse{
-		ID:             user.ID,
-		Username:       user.Username,
-		Nickname:       user.Nickname,
-		Email:          user.Email,
-		EmailVerified:  user.EmailVerified,
-		Avatar:         getAvatarOrDefault(user),
-		CoverURL:       user.CoverURL,
-		Bio:            user.Bio,
-		Website:        user.Website,
-		Location:       user.Location,
-		PostsCount:     user.PostsCount,
-		FollowersCount: user.FollowersCount,
-		FollowingCount: user.FollowingCount,
-		IsVerified:     user.IsVerified,
-		CreatedAt:      FormatTime(user.CreatedAt),
+		ID:              user.ID,
+		Username:        user.Username,
+		Nickname:        user.Nickname,
+		Email:           user.Email,
+		EmailVerified:   user.EmailVerified,
+		Avatar:          getAvatarOrDefault(user),
+		CoverURL:        user.CoverURL,
+		Bio:             user.Bio,
+		Website:         user.Website,
+		Location:        user.Location,
+		PostsCount:      user.PostsCount,
+		FollowersCount:  user.FollowersCount,
+		FollowingCount:  user.FollowingCount,
+		IsVerified:      user.IsVerified,
+		CreatedAt:       FormatTime(user.CreatedAt),
+		PrivacySettings: convertPrivacySettingsToResponse(&user.PrivacySettings),
 	}
 }
 
@@ -183,22 +197,23 @@ func ConvertUserToDetailResponseWithPostsCount(user *model.User, postsCount int)
 		return nil
 	}
 	return &UserDetailResponse{
-		ID:             user.ID,
-		Username:       user.Username,
-		Nickname:       user.Nickname,
-		Email:          user.Email,
-		EmailVerified:  user.EmailVerified,
-		Phone:          user.Phone,
-		Avatar:         getAvatarOrDefault(user),
-		CoverURL:       user.CoverURL,
-		Bio:            user.Bio,
-		Website:        user.Website,
-		Location:       user.Location,
-		PostsCount:     postsCount,
-		FollowersCount: user.FollowersCount,
-		FollowingCount: user.FollowingCount,
-		IsVerified:     user.IsVerified,
-		CreatedAt:      FormatTime(user.CreatedAt),
+		ID:              user.ID,
+		Username:        user.Username,
+		Nickname:        user.Nickname,
+		Email:           user.Email,
+		EmailVerified:   user.EmailVerified,
+		Phone:           user.Phone,
+		Avatar:          getAvatarOrDefault(user),
+		CoverURL:        user.CoverURL,
+		Bio:             user.Bio,
+		Website:         user.Website,
+		Location:        user.Location,
+		PostsCount:      postsCount,
+		FollowersCount:  user.FollowersCount,
+		FollowingCount:  user.FollowingCount,
+		IsVerified:      user.IsVerified,
+		CreatedAt:       FormatTime(user.CreatedAt),
+		PrivacySettings: convertPrivacySettingsToResponse(&user.PrivacySettings),
 	}
 }