feat(moderation): add manual content review system with three-tier AI moderation

Add admin comment moderation endpoints (single and batch) and introduce a three-tier moderation system (pass/review/block) for content flagged by AI. Content with unclear violations is now held for manual review instead of being auto-rejected. Deleted the legacy audit_service.go in favor of the unified hook-based moderation system.

internal/pkg/hook/moderation_hooks.go

@@ -10,11 +10,8 @@ import (
 	"go.uber.org/zap"
 )
 
-type PostModerationHook struct {
-	name          string
-	postAIService PostAIService
-	postRepo      repository.PostRepository
-	strictMode    bool
+type reviewableError interface {
+	IsReview() bool
 }
 
 type PostAIService interface {
@@ -23,6 +20,13 @@ type PostAIService interface {
 	ModerateComment(ctx context.Context, content string, images []string) error
 }
 
+type PostModerationHook struct {
+	name          string
+	postAIService PostAIService
+	postRepo      repository.PostRepository
+	strictMode    bool
+}
+
 func NewPostModerationHook(postAIService PostAIService, postRepo repository.PostRepository, strictMode bool) *PostModerationHook {
 	return &PostModerationHook{
 		name:          "moderation.post.ai",
@@ -36,9 +40,9 @@ func (h *PostModerationHook) Register(manager *Manager) {
 	manager.Register(&Hook{
 		Name:     h.name,
 		HookType: HookPostPreModerate,
-		Priority: PriorityHighest,
+		Priority: PriorityHigh,
 		Func:     h.Execute,
-		Async:    false, // 必须同步执行，因为调用方需要审核结果
+		Async:    false,
 		Timeout:  30 * time.Second,
 	})
 }
@@ -54,20 +58,32 @@ func (h *PostModerationHook) Execute(ctx *HookContext) error {
 		return nil
 	}
 
+	if result.RejectReason != "" || result.NeedsReview {
+		return nil
+	}
+
 	if h.postAIService == nil || !h.postAIService.IsEnabled() {
 		result.Approved = true
 		result.ReviewedBy = "system"
-		zap.L().Debug("AI moderation disabled, auto approve post",
-			zap.String("post_id", data.PostID),
-		)
 		return nil
 	}
 
 	err := h.postAIService.ModeratePost(ctx.Ctx, data.Title, data.Content, data.Images)
 	if err != nil {
-		if rejectErr, ok := err.(interface{ UserMessage() string }); ok {
+		if userErr, ok := err.(interface{ UserMessage() string }); ok {
+			if revErr, ok := err.(reviewableError); ok && revErr.IsReview() {
+				result.Approved = false
+				result.NeedsReview = true
+				result.RejectReason = userErr.UserMessage()
+				result.ReviewedBy = "ai"
+				zap.L().Info("Post flagged for manual review by AI",
+					zap.String("post_id", data.PostID),
+					zap.String("reason", result.RejectReason),
+				)
+				return nil
+			}
 			result.Approved = false
-			result.RejectReason = rejectErr.UserMessage()
+			result.RejectReason = userErr.UserMessage()
 			result.ReviewedBy = "ai"
 			zap.L().Info("Post rejected by AI moderation",
 				zap.String("post_id", data.PostID),
@@ -98,9 +114,6 @@ func (h *PostModerationHook) Execute(ctx *HookContext) error {
 
 	result.Approved = true
 	result.ReviewedBy = "ai"
-	zap.L().Debug("Post approved by AI moderation",
-		zap.String("post_id", data.PostID),
-	)
 	return nil
 }
 
@@ -124,9 +137,9 @@ func (h *CommentModerationHook) Register(manager *Manager) {
 	manager.Register(&Hook{
 		Name:     h.name,
 		HookType: HookCommentPreModerate,
-		Priority: PriorityHighest,
+		Priority: PriorityHigh,
 		Func:     h.Execute,
-		Async:    false, // 必须同步执行，因为调用方需要审核结果
+		Async:    false,
 		Timeout:  30 * time.Second,
 	})
 }
@@ -142,20 +155,32 @@ func (h *CommentModerationHook) Execute(ctx *HookContext) error {
 		return nil
 	}
 
+	if result.RejectReason != "" || result.NeedsReview {
+		return nil
+	}
+
 	if h.postAIService == nil || !h.postAIService.IsEnabled() {
 		result.Approved = true
 		result.ReviewedBy = "system"
-		zap.L().Debug("AI moderation disabled, auto approve comment",
-			zap.String("comment_id", data.CommentID),
-		)
 		return nil
 	}
 
 	err := h.postAIService.ModerateComment(ctx.Ctx, data.Content, data.Images)
 	if err != nil {
-		if rejectErr, ok := err.(interface{ UserMessage() string }); ok {
+		if userErr, ok := err.(interface{ UserMessage() string }); ok {
+			if revErr, ok := err.(reviewableError); ok && revErr.IsReview() {
+				result.Approved = false
+				result.NeedsReview = true
+				result.RejectReason = userErr.UserMessage()
+				result.ReviewedBy = "ai"
+				zap.L().Info("Comment flagged for manual review by AI",
+					zap.String("comment_id", data.CommentID),
+					zap.String("reason", result.RejectReason),
+				)
+				return nil
+			}
 			result.Approved = false
-			result.RejectReason = rejectErr.UserMessage()
+			result.RejectReason = userErr.UserMessage()
 			result.ReviewedBy = "ai"
 			zap.L().Info("Comment rejected by AI moderation",
 				zap.String("comment_id", data.CommentID),
@@ -177,7 +202,7 @@ func (h *CommentModerationHook) Execute(ctx *HookContext) error {
 
 		result.Approved = true
 		result.ReviewedBy = "system"
-		zap.L().Warn("AI comment moderation error, fallback approve",
+		zap.L().Warn("AI moderation error, fallback approve",
 			zap.String("comment_id", data.CommentID),
 			zap.Error(err),
 		)
@@ -186,23 +211,20 @@ func (h *CommentModerationHook) Execute(ctx *HookContext) error {
 
 	result.Approved = true
 	result.ReviewedBy = "ai"
-	zap.L().Debug("Comment approved by AI moderation",
-		zap.String("comment_id", data.CommentID),
-	)
 	return nil
 }
 
+type SensitiveService interface {
+	Check(ctx context.Context, text string) (bool, []string)
+	Replace(ctx context.Context, text string, repl string) string
+}
+
 type SensitiveWordHook struct {
 	name       string
 	sensitive  SensitiveService
 	replaceStr string
 }
 
-type SensitiveService interface {
-	Check(ctx context.Context, text string) (bool, []string)
-	Replace(ctx context.Context, text string, repl string) string
-}
-
 func NewSensitiveWordHook(sensitive SensitiveService, replaceStr string) *SensitiveWordHook {
 	return &SensitiveWordHook{
 		name:       "moderation.sensitive_word",
@@ -215,7 +237,7 @@ func (h *SensitiveWordHook) RegisterPostHook(manager *Manager) {
 	manager.Register(&Hook{
 		Name:     h.name + ".post",
 		HookType: HookPostPreModerate,
-		Priority: PriorityHigh,
+		Priority: PriorityHighest,
 		Func:     h.executePost,
 		Async:    false,
 	})
@@ -225,7 +247,7 @@ func (h *SensitiveWordHook) RegisterCommentHook(manager *Manager) {
 	manager.Register(&Hook{
 		Name:     h.name + ".comment",
 		HookType: HookCommentPreModerate,
-		Priority: PriorityHigh,
+		Priority: PriorityHighest,
 		Func:     h.executeComment,
 		Async:    false,
 	})
@@ -325,18 +347,18 @@ func NewModerationHooks(
 }
 
 func (m *ModerationHooks) RegisterAll(manager *Manager) {
-	postHook := NewPostModerationHook(m.postAIService, m.postRepo, m.strictMode)
-	postHook.Register(manager)
-
-	commentHook := NewCommentModerationHook(m.postAIService, m.commentRepo, m.strictMode)
-	commentHook.Register(manager)
-
 	if m.sensitiveService != nil {
 		sensitiveHook := NewSensitiveWordHook(m.sensitiveService, m.replaceStr)
 		sensitiveHook.RegisterPostHook(manager)
 		sensitiveHook.RegisterCommentHook(manager)
 	}
 
+	postHook := NewPostModerationHook(m.postAIService, m.postRepo, m.strictMode)
+	postHook.Register(manager)
+
+	commentHook := NewCommentModerationHook(m.postAIService, m.commentRepo, m.strictMode)
+	commentHook.Register(manager)
+
 	zap.L().Info("Registered moderation hooks",
 		zap.Bool("ai_enabled", m.postAIService != nil && m.postAIService.IsEnabled()),
 		zap.Bool("sensitive_enabled", m.sensitiveService != nil),