feat(api): add message segments support for posts and comments

Add rich message segment support enabling structured content (text, images, votes, mentions) in posts and comments. Includes segments field in models, DTOs, handlers, and services. Also adds @mention notification processing and migrates vote data to embedded segments.

internal/repository/user_repo.go

@@ -1,9 +1,9 @@
-package repository
+package repository
 
 import (
-	"with_you/internal/model"
 	"strings"
 	"time"
+	"with_you/internal/model"
 
 	"gorm.io/gorm"
 	"gorm.io/gorm/clause"

internal/repository/vote_repo.go

@@ -1,8 +1,8 @@
-package repository
+package repository
 
 import (
-	"with_you/internal/model"
 	"errors"
+	"with_you/internal/model"
 
 	"gorm.io/gorm"
 )
@@ -16,6 +16,7 @@ type VoteRepository interface {
 	GetUserVote(postID, userID string) (*model.UserVote, error)
 	UpdateOption(optionID, content string) error
 	DeleteOptionsByPostID(postID string) error
+	CountVotesByOption(postID, optionID string) (int, error)
 }
 
 // voteRepository 投票仓储实现
@@ -72,9 +73,9 @@ func (r *voteRepository) Vote(postID, userID, optionID string) error {
 		// 验证选项是否属于该帖子
 		var option model.VoteOption
 		if err := tx.Where("id = ? AND post_id = ?", optionID, postID).First(&option).Error; err != nil {
-		if errors.Is(err, gorm.ErrRecordNotFound) {
-			return errors.New("invalid option")
-		}
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return errors.New("invalid option")
+			}
 			return err
 		}
 
@@ -100,9 +101,9 @@ func (r *voteRepository) Unvote(postID, userID string) error {
 		var userVote model.UserVote
 		err := tx.Where("post_id = ? AND user_id = ?", postID, userID).First(&userVote).Error
 		if err != nil {
-		if errors.Is(err, gorm.ErrRecordNotFound) {
-			return nil // 没有投票记录，直接返回
-		}
+			if errors.Is(err, gorm.ErrRecordNotFound) {
+				return nil // 没有投票记录，直接返回
+			}
 			return err
 		}
 
@@ -144,12 +145,16 @@ func (r *voteRepository) UpdateOption(optionID, content string) error {
 // DeleteOptionsByPostID 删除帖子的所有投票选项
 func (r *voteRepository) DeleteOptionsByPostID(postID string) error {
 	return r.db.Transaction(func(tx *gorm.DB) error {
-		// 删除关联的用户投票记录
 		if err := tx.Where("post_id = ?", postID).Delete(&model.UserVote{}).Error; err != nil {
 			return err
 		}
-
-		// 删除投票选项
 		return tx.Where("post_id = ?", postID).Delete(&model.VoteOption{}).Error
 	})
 }
+
+// CountVotesByOption 统计指定选项的投票数
+func (r *voteRepository) CountVotesByOption(postID, optionID string) (int, error) {
+	var count int64
+	err := r.db.Model(&model.UserVote{}).Where("post_id = ? AND option_id = ?", postID, optionID).Count(&count).Error
+	return int(count), err
+}