fix(canvas): parse assistant media from structured message parts

components/canvas/CanvasChatPanel.tsx

@@ -3071,10 +3071,64 @@ export function CanvasChatPanel({ chatId, initialMessages = [], onClose, onOpenF
           continue;
         }
 
-        const content = message.parts?.map((p: any) => p.text || "").join("") || "";
         const nearestUserImageKeys = getNearestUserImageUrlKeys(messages, messageIndex);
-        const imageUrls = extractAssistantImageUrls(content, nearestUserImageKeys);
-        const videoUrls = extractVideoUrls(content);
+        const imageUrlSet = new Set<string>();
+        const videoUrlSet = new Set<string>();
+        const parts = (message.parts || []) as any[];
+
+        parts.forEach((part) => {
+          if (!part) return;
+
+          if (part.type === "text" && typeof part.text === "string") {
+            extractAssistantImageUrls(part.text, nearestUserImageKeys).forEach((url) =>
+              imageUrlSet.add(url)
+            );
+            extractVideoUrls(part.text).forEach((url) => videoUrlSet.add(url));
+            return;
+          }
+
+          const rawUrl =
+            typeof part.url === "string" && part.url.trim()
+              ? part.url.trim()
+              : typeof part.data === "string" && part.data.trim()
+                ? part.data.trim()
+                : "";
+          if (!rawUrl || !/^https?:\/\//i.test(rawUrl)) return;
+
+          const mediaType = String(
+            part.mediaType || part.mimeType || part.contentType || ""
+          ).toLowerCase();
+          if (
+            mediaType.startsWith("video/") ||
+            /\.(mp4|mov|webm|m4v)(?:[?#].*)?$/i.test(rawUrl)
+          ) {
+            videoUrlSet.add(rawUrl);
+            return;
+          }
+
+          imageUrlSet.add(rawUrl);
+        });
+
+        const messageAttachments = ((message as any).attachments || []) as Array<{
+          url?: string;
+          contentType?: string;
+        }>;
+        messageAttachments.forEach((attachment) => {
+          const rawUrl = String(attachment?.url || "").trim();
+          if (!rawUrl || !/^https?:\/\//i.test(rawUrl)) return;
+          const contentType = String(attachment?.contentType || "").toLowerCase();
+          if (
+            contentType.startsWith("video/") ||
+            /\.(mp4|mov|webm|m4v)(?:[?#].*)?$/i.test(rawUrl)
+          ) {
+            videoUrlSet.add(rawUrl);
+            return;
+          }
+          imageUrlSet.add(rawUrl);
+        });
+
+        const imageUrls = Array.from(imageUrlSet);
+        const videoUrls = Array.from(videoUrlSet);
         if (imageUrls.length === 0 && videoUrls.length === 0) continue;
 
         processedMessageIds.current.add(message.id);