fix: add 3s timeout to sync link preview fetch, async fallback

go-backend/internal/handlers/post_handler.go

@@ -575,15 +575,20 @@ func (h *PostHandler) CreatePost(c *gin.Context) {
 		h.moderationService.LogAIDecision(c.Request.Context(), "post", post.ID, userID, req.Body, scores, nil, decision, flagReason, orDecision, nil)
 	}
 
-	// Auto-extract link preview from post body (synchronous so it's in the response)
+	// Auto-extract link preview from post body
+	// Try synchronously with a short timeout so the response isn't blocked.
+	// If it times out, fall back to async so it's saved for later views.
 	if h.linkPreviewService != nil {
 		linkURL := services.ExtractFirstURL(req.Body)
 		if linkURL != "" {
-			// Check if author is an official account (trusted = skip safety checks)
 			var isOfficial bool
 			_ = h.postRepo.Pool().QueryRow(c.Request.Context(), `SELECT COALESCE(is_official, false) FROM profiles WHERE id = $1`, userID).Scan(&isOfficial)
 
-			lp, lpErr := h.linkPreviewService.FetchPreview(c.Request.Context(), linkURL, isOfficial)
+			// 3-second budget for synchronous fetch
+			fastCtx, fastCancel := context.WithTimeout(c.Request.Context(), 3*time.Second)
+			lp, lpErr := h.linkPreviewService.FetchPreview(fastCtx, linkURL, isOfficial)
+			fastCancel()
+
 			if lpErr == nil && lp != nil {
 				_ = h.linkPreviewService.SaveLinkPreview(c.Request.Context(), post.ID.String(), lp)
 				post.LinkPreviewURL = &lp.URL
@@ -591,6 +596,17 @@ func (h *PostHandler) CreatePost(c *gin.Context) {
 				post.LinkPreviewDescription = &lp.Description
 				post.LinkPreviewImageURL = &lp.ImageURL
 				post.LinkPreviewSiteName = &lp.SiteName
+			} else if lpErr != nil {
+				// Timed out or failed — fire async so it's saved for later views
+				postID := post.ID.String()
+				go func() {
+					bgCtx, bgCancel := context.WithTimeout(context.Background(), 10*time.Second)
+					defer bgCancel()
+					bgLp, bgErr := h.linkPreviewService.FetchPreview(bgCtx, linkURL, isOfficial)
+					if bgErr == nil && bgLp != nil {
+						_ = h.linkPreviewService.SaveLinkPreview(bgCtx, postID, bgLp)
+					}
+				}()
 			}
 		}
 	}