chore: exclude platform-side stale zh URLs from link checker

.github/workflows/check-links.yml

@@ -58,6 +58,23 @@ jobs:
             # and translated variants.
             "buildwithfern\\.com/learn/dashboard/assets/pdf-ui\\.png",
             "buildwithfern\\.com/learn/zh/dashboard/assets/pdf-ui\\.png",
+
+            # Platform-side stale Chinese (zh) translation rendering bugs.
+            # These URLs are valid in source and the English equivalents serve 200,
+            # but the Chinese-locale rendering on buildwithfern.com is broken:
+            #   1. /products/sdks/custom-code.mdx — appears in the rendered Chinese
+            #      readme page even though both English source and Chinese translation
+            #      source have linked to /learn/sdks/overview/custom-code since
+            #      fern-api/docs#5348 (May 5). The Chinese translation S3 blob is
+            #      stale despite multiple successful Publish Docs runs.
+            #   2. /learn/zh/docs/ai-features/ask-fern/api-reference/code/get-code-records
+            #      — listed in sitemap-zh.xml, .md content serves 200, but HTML page
+            #      returns 404 (English equivalent serves 200).
+            # TODO: remove these excludes once fern-api/fern-platform fixes the
+            # underlying translation rendering bugs (FDR registerTranslation /
+            # docs bundle locale routing). Tracked in PR #5409.
+            "buildwithfern\\.com/products/sdks/custom-code\\.mdx",
+            "buildwithfern\\.com/learn/zh/docs/ai-features/ask-fern/api-reference/code/get-code-records",
 
             # Sites that block automated requests
             "^https://docs\\.stack-auth\\.com",