fix: surface chat stream provider failures

app/(chat)/api/chat/route.ts

@@ -1192,6 +1192,46 @@ function getDirectAgentToolErrorMessage(
   }
 }
 
+function getChatStreamErrorMessage(error: unknown): string {
+  const rawMessage =
+    error instanceof Error ? String(error.message || "").trim() : String(error || "").trim();
+  const normalized = rawMessage.toLowerCase();
+
+  if (
+    normalized.includes("token quota is not enough") ||
+    normalized.includes("pre_consume_token_quota_failed") ||
+    normalized.includes("quota is not enough")
+  ) {
+    return "当前对话模型额度不足，请切换其他模型，或联系管理员补充该模型额度。";
+  }
+
+  if (
+    normalized.includes("timeout") ||
+    normalized.includes("timed out") ||
+    normalized.includes("body timeout")
+  ) {
+    return "当前对话模型响应超时，请重试，或切换到其他可用模型。";
+  }
+
+  if (rawMessage) {
+    return `当前对话暂时失败：${rawMessage}`;
+  }
+
+  return "当前对话暂时失败，请重试或切换其他模型。";
+}
+
+function normalizeAssistantPartsForPersistence(parts: Array<Record<string, any>> | undefined) {
+  const safeParts = Array.isArray(parts) ? parts.filter(Boolean) : [];
+  return safeParts.filter((part) => {
+    const partType = String(part?.type || "").trim();
+    if (!partType) return false;
+    if (partType === "data-keepalive" || partType === "step-start" || partType === "step-finish") {
+      return false;
+    }
+    return true;
+  });
+}
+
 function buildAgentToolImageMarkdown(params: {
   originalUrl: string;
   thumbnailUrl?: string | null;
@@ -9187,11 +9227,19 @@ export async function POST(request: Request) {
           },
         });
 
-          result.consumeStream();
+          result.consumeStream({
+            onError: (error) => {
+              console.error("[Chat API] streamText consume error:", error);
+            },
+          });
 
           dataStream.merge(
             result.toUIMessageStream({
               sendReasoning: true,
+              onError: (error) => {
+                console.error("[Chat API] streamText ui stream error:", error);
+                return getChatStreamErrorMessage(error);
+              },
             })
           );
         } finally {
@@ -9203,11 +9251,39 @@ export async function POST(request: Request) {
       onFinish: async ({ messages }) => {
         stopStreamKeepalive?.();
         stopStreamKeepalive = null;
-        await saveMessages({
-          messages: messages.map((currentMessage) => ({
+        const messagesToPersist: Array<{
+          id: string;
+          role: string;
+          parts: unknown;
+          createdAt: Date;
+          attachments: unknown;
+          chatId: string;
+          videoStorageStatus: null;
+          temporaryVideoUrl: null;
+          permanentVideoUrl: null;
+          archivedAt: null;
+          videoMetadata: null;
+        }> = [];
+
+        for (const currentMessage of messages) {
+          const normalizedParts =
+            currentMessage.role === "assistant"
+              ? normalizeAssistantPartsForPersistence(
+                  currentMessage.parts as Array<Record<string, any>> | undefined,
+                )
+              : currentMessage.parts;
+
+          if (
+            currentMessage.role === "assistant" &&
+            (!Array.isArray(normalizedParts) || normalizedParts.length === 0)
+          ) {
+            continue;
+          }
+
+          messagesToPersist.push({
             id: currentMessage.id,
             role: currentMessage.role,
-            parts: currentMessage.parts,
+            parts: normalizedParts,
             createdAt: new Date(),
             attachments: [],
             chatId: id,
@@ -9216,8 +9292,14 @@ export async function POST(request: Request) {
             permanentVideoUrl: null,
             archivedAt: null,
             videoMetadata: null,
-          })),
-        });
+          });
+        }
+
+        if (messagesToPersist.length > 0) {
+          await saveMessages({
+            messages: messagesToPersist,
+          });
+        }
 
         // 检测助手消息中是否包含视频，如果有则立即标记并归档到永久存储
         for (const msg of messages) {