refactor: replace standard log with zap logger and optimize code patterns

- Migrate all log.Printf/log.Println calls to structured zap logging
- Use cmp.Or for cleaner default value handling
- Replace manual loops with slices.ContainsFunc/IndexFunc
- Add batch query methods (IsLikedBatch, IsFavoritedBatch) to solve N+1 problem
- Update JSON tags from omitempty to omitzero for numeric fields
- Use errgroup-style wg.Go for worker goroutines
- Remove duplicate casbin/v2 dependency (keeping v3)
- Add plans/ to gitignore

internal/service/post_service.go

@@ -514,10 +514,9 @@ func (s *postServiceImpl) GetPostInteractionStatus(ctx context.Context, postIDs
 		return isLikedMap, isFavoritedMap, nil
 	}
 
-	for _, postID := range postIDs {
-		isLikedMap[postID] = s.postRepo.IsLiked(postID, userID)
-		isFavoritedMap[postID] = s.postRepo.IsFavorited(postID, userID)
-	}
+	// 使用批量查询替代循环中的单个查询，解决 N+1 问题
+	isLikedMap = s.postRepo.IsLikedBatch(postIDs, userID)
+	isFavoritedMap = s.postRepo.IsFavoritedBatch(postIDs, userID)
 
 	return isLikedMap, isFavoritedMap, nil
 }