fix: gate detail references by selected brand

app/api/agent-workflow/reference-search/route.ts

@@ -366,10 +366,12 @@ function isBrandNameMatched(
   const normalizedBrandName = normalizeComparableName(candidateBrandName);
   if (!normalizedBrandName) return false;
 
+  if (normalizedBrandName === normalizedRequestedBrand) return true;
+
+  // 只允许“候选品牌包含当前品牌”的弱匹配，避免短品牌名反向包含导致串品牌。
   return (
-    normalizedBrandName === normalizedRequestedBrand ||
-    normalizedBrandName.includes(normalizedRequestedBrand) ||
-    normalizedRequestedBrand.includes(normalizedBrandName)
+    normalizedRequestedBrand.length >= 2 &&
+    normalizedBrandName.includes(normalizedRequestedBrand)
   );
 }
 
@@ -452,11 +454,6 @@ export async function GET(request: NextRequest) {
       resourceType: "task-detail",
       [queryType]: normalizedKeyword,
     });
-    if (requestedBrandName) {
-      upstreamParams.set("brandName", requestedBrandName);
-      upstreamParams.set("brand", requestedBrandName);
-      upstreamParams.set("productBrand", requestedBrandName);
-    }
     const upstreamUrl = `${normalizeBaseUrl(
       config.baseUrl
     )}/standard-model-white-background?${upstreamParams.toString()}`;
@@ -475,6 +472,27 @@ export async function GET(request: NextRequest) {
       const errorMessage =
         String(upstreamResult.error?.message || "").trim() ||
         `参考图搜索失败(${upstreamResponse.status})`;
+      if (
+        requestedBrandName &&
+        (errorCode === "TASK_DETAIL_NOT_FOUND" || errorCode === "FULL_SET_NOT_FOUND")
+      ) {
+        return jsonNoStore(
+          {
+            success: false,
+            error: {
+              code: "BRAND_REFERENCE_NOT_FOUND",
+              message: `当前品牌「${requestedBrandName}」下没有可用的${
+                parsed.target === "main"
+                  ? "主图参考图"
+                  : parsed.target === "detail"
+                    ? "详情参考图"
+                    : "SKU参考图"
+              }`,
+            },
+          },
+          { status: 404 }
+        );
+      }
       return jsonNoStore(
         {
           success: false,
@@ -488,14 +506,44 @@ export async function GET(request: NextRequest) {
     }
 
     const upstreamBrandName = getExternalBrandName(upstreamResult.data);
-    const fallbackBrandName =
-      upstreamBrandName ||
-      (verifiedGoodsBrandName &&
-      isBrandNameMatched(verifiedGoodsBrandName, requestedBrandName)
-        ? verifiedGoodsBrandName
-        : null);
+    const rawCandidates = upstreamResult.data.candidates || [];
+    const candidateBrandSamples = Array.from(
+      new Set(
+        rawCandidates
+          .map((candidate) => getExternalBrandName(candidate))
+          .filter((brandName): brandName is string => Boolean(brandName))
+      )
+    ).slice(0, 8);
+    if (requestedBrandName) {
+      console.info("[Agent Workflow Reference Search] Brand gate:", {
+        keyword: normalizedKeyword,
+        queryType,
+        target: parsed.target,
+        requestedBrandName,
+        verifiedGoodsBrandName,
+        upstreamBrandName,
+        candidateCount: rawCandidates.length,
+        candidateBrandSamples,
+      });
+    }
+    const hasVerifiedRequestedBrand =
+      Boolean(verifiedGoodsBrandName) &&
+      isBrandNameMatched(verifiedGoodsBrandName, requestedBrandName);
+    const hasUpstreamRequestedBrand =
+      Boolean(upstreamBrandName) &&
+      isBrandNameMatched(upstreamBrandName, requestedBrandName);
+    let fallbackBrandName: string | null = null;
+    if (requestedBrandName) {
+      if (hasVerifiedRequestedBrand) {
+        fallbackBrandName = verifiedGoodsBrandName || null;
+      } else if (hasUpstreamRequestedBrand) {
+        fallbackBrandName = upstreamBrandName || null;
+      }
+    } else {
+      fallbackBrandName = upstreamBrandName;
+    }
     const sortedCandidates = sortCandidatesByUploadedAtDesc(
-      (upstreamResult.data.candidates || []).map((item, index) =>
+      rawCandidates.map((item, index) =>
         normalizeCandidate(item, index, fallbackBrandName)
       )
     );
@@ -550,7 +598,6 @@ export async function GET(request: NextRequest) {
         brandName:
           selectedCandidate.brandName ||
           fallbackBrandName ||
-          requestedBrandName ||
           null,
         categoryName: selectedCandidate.categoryName || String(upstreamResult.data.categoryName || "").trim() || null,
         shopName: selectedCandidate.shopName || String(upstreamResult.data.shopName || "").trim() || null,