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/comment_service.go

@@ -4,13 +4,14 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"log"
 	"strings"
 
 	"carrot_bbs/internal/cache"
 	"carrot_bbs/internal/model"
 	"carrot_bbs/internal/pkg/gorse"
 	"carrot_bbs/internal/repository"
+
+	"go.uber.org/zap"
 )
 
 // CommentService 评论服务
@@ -115,11 +116,16 @@ func (s *CommentService) reviewCommentAsync(
 	// 未启用AI时，直接通过审核并发送后续通知
 	if s.postAIService == nil || !s.postAIService.IsEnabled() {
 		if err := s.commentRepo.UpdateModerationStatus(commentID, model.CommentStatusPublished); err != nil {
-			log.Printf("[WARN] Failed to publish comment without AI moderation: %v", err)
+			zap.L().Warn("Failed to publish comment without AI moderation",
+				zap.Error(err),
+			)
 			return
 		}
 		if err := s.applyCommentPublishedStats(commentID); err != nil {
-			log.Printf("[WARN] Failed to apply published stats for comment %s: %v", commentID, err)
+			zap.L().Warn("Failed to apply published stats for comment",
+				zap.String("commentID", commentID),
+				zap.Error(err),
+			)
 		}
 		s.invalidatePostCaches(postID)
 		s.afterCommentPublished(userID, postID, commentID, parentID, parentUserID, postOwnerID)
@@ -131,7 +137,10 @@ func (s *CommentService) reviewCommentAsync(
 		var rejectedErr *CommentModerationRejectedError
 		if errors.As(err, &rejectedErr) {
 			if delErr := s.commentRepo.Delete(commentID); delErr != nil {
-				log.Printf("[WARN] Failed to delete rejected comment %s: %v", commentID, delErr)
+				zap.L().Warn("Failed to delete rejected comment",
+					zap.String("commentID", commentID),
+					zap.Error(delErr),
+				)
 			}
 			s.notifyCommentModerationRejected(userID, rejectedErr.Reason)
 			return
@@ -139,24 +148,39 @@ func (s *CommentService) reviewCommentAsync(
 
 		// 审核服务异常时降级放行，避免评论长期pending
 		if updateErr := s.commentRepo.UpdateModerationStatus(commentID, model.CommentStatusPublished); updateErr != nil {
-			log.Printf("[WARN] Failed to publish comment %s after moderation error: %v", commentID, updateErr)
+			zap.L().Warn("Failed to publish comment after moderation error",
+				zap.String("commentID", commentID),
+				zap.Error(updateErr),
+			)
 			return
 		}
 		if statsErr := s.applyCommentPublishedStats(commentID); statsErr != nil {
-			log.Printf("[WARN] Failed to apply published stats for comment %s: %v", commentID, statsErr)
+			zap.L().Warn("Failed to apply published stats for comment",
+				zap.String("commentID", commentID),
+				zap.Error(statsErr),
+			)
 		}
 		s.invalidatePostCaches(postID)
-		log.Printf("[WARN] Comment moderation failed, fallback publish comment=%s err=%v", commentID, err)
+		zap.L().Warn("Comment moderation failed, fallback publish comment",
+			zap.String("commentID", commentID),
+			zap.Error(err),
+		)
 		s.afterCommentPublished(userID, postID, commentID, parentID, parentUserID, postOwnerID)
 		return
 	}
 
 	if updateErr := s.commentRepo.UpdateModerationStatus(commentID, model.CommentStatusPublished); updateErr != nil {
-		log.Printf("[WARN] Failed to publish comment %s: %v", commentID, updateErr)
+		zap.L().Warn("Failed to publish comment",
+			zap.String("commentID", commentID),
+			zap.Error(updateErr),
+		)
 		return
 	}
 	if statsErr := s.applyCommentPublishedStats(commentID); statsErr != nil {
-		log.Printf("[WARN] Failed to apply published stats for comment %s: %v", commentID, statsErr)
+		zap.L().Warn("Failed to apply published stats for comment",
+			zap.String("commentID", commentID),
+			zap.Error(statsErr),
+		)
 	}
 	s.invalidatePostCaches(postID)
 	s.afterCommentPublished(userID, postID, commentID, parentID, parentUserID, postOwnerID)
@@ -184,7 +208,9 @@ func (s *CommentService) afterCommentPublished(userID, postID, commentID string,
 				if parentUserID != userID {
 					notifyErr := s.systemMessageService.SendReplyNotification(context.Background(), parentUserID, userID, postID, *parentID, commentID)
 					if notifyErr != nil {
-						log.Printf("[ERROR] Error sending reply notification: %v", notifyErr)
+						zap.L().Error("Error sending reply notification",
+							zap.Error(notifyErr),
+						)
 					}
 				}
 			} else {
@@ -192,7 +218,9 @@ func (s *CommentService) afterCommentPublished(userID, postID, commentID string,
 				if postOwnerID != userID {
 					notifyErr := s.systemMessageService.SendCommentNotification(context.Background(), postOwnerID, userID, postID, commentID)
 					if notifyErr != nil {
-						log.Printf("[ERROR] Error sending comment notification: %v", notifyErr)
+						zap.L().Error("Error sending comment notification",
+							zap.Error(notifyErr),
+						)
 					}
 				}
 			}
@@ -203,7 +231,9 @@ func (s *CommentService) afterCommentPublished(userID, postID, commentID string,
 	go func() {
 		if s.gorseClient.IsEnabled() {
 			if err := s.gorseClient.InsertFeedback(context.Background(), gorse.FeedbackTypeComment, userID, postID); err != nil {
-				log.Printf("[WARN] Failed to insert comment feedback to Gorse: %v", err)
+				zap.L().Warn("Failed to insert comment feedback to Gorse",
+					zap.Error(err),
+				)
 			}
 		}
 	}()
@@ -226,7 +256,9 @@ func (s *CommentService) notifyCommentModerationRejected(userID, reason string)
 			"评论审核未通过",
 			content,
 		); err != nil {
-			log.Printf("[WARN] Failed to send comment moderation reject notification: %v", err)
+			zap.L().Warn("Failed to send comment moderation reject notification",
+				zap.Error(err),
+			)
 		}
 	}()
 }
@@ -307,7 +339,9 @@ func (s *CommentService) Like(ctx context.Context, commentID, userID string) err
 				)
 			}
 			if notifyErr != nil {
-				log.Printf("[ERROR] Error sending like notification: %v", notifyErr)
+				zap.L().Error("Error sending like notification",
+					zap.Error(notifyErr),
+				)
 			}
 		}()
 	}