feat(moderation): make moderation more lenient and add timeout fallback behavior

The moderation system now uses a "pass/review" strategy instead of "pass/review/block", treating hard violations the same as review (only routing to manual review rather than auto-rejecting). Add fallback-approve behavior in the hook system so slow moderation APIs never silently block normal content when they time out or get cancelled - timed-out moderation now approves with "ReviewedBy: system" instead of leaving the zero-value result that would reject content. Update post/comment/vote services and handlers to use the new unified behavior. Simplify moderation prompts to emphasize "宁可放过，不可误伤" (prefer false positives over false negatives).

internal/handler/post_handler.go

@@ -106,13 +106,8 @@ func (h *PostHandler) Create(c *gin.Context) {
 		return
 	}
 
-	post, err := h.postService.Create(c.Request.Context(), userID, req.Title, content, segments, req.Images, req.ChannelID, req.ClientRequestID)
+		post, err := h.postService.Create(c.Request.Context(), userID, req.Title, content, segments, req.Images, req.ChannelID, req.ClientRequestID)
 	if err != nil {
-		var moderationErr *service.PostModerationRejectedError
-		if errors.As(err, &moderationErr) {
-			response.BadRequest(c, moderationErr.UserMessage())
-			return
-		}
 		// 幂等命中"进行中"占位：提示客户端稍候，避免重复提交
 		if errors.Is(err, service.ErrDuplicatePostRequest) {
 			response.ErrorWithStatusCode(c, http.StatusTooManyRequests, 429, err.Error())

internal/handler/vote_handler.go

@@ -42,11 +42,6 @@ func (h *VoteHandler) CreateVotePost(c *gin.Context) {
 
 	post, err := h.voteService.CreateVotePost(c.Request.Context(), userID, &req)
 	if err != nil {
-		var moderationErr *service.PostModerationRejectedError
-		if errors.As(err, &moderationErr) {
-			response.BadRequest(c, moderationErr.UserMessage())
-			return
-		}
 		// 幂等命中"进行中"占位：提示客户端稍候，避免重复提交
 		if errors.Is(err, service.ErrDuplicatePostRequest) {
 			response.ErrorWithStatusCode(c, http.StatusTooManyRequests, 429, err.Error())