Persist structured failure manifests

README.md

@@ -194,6 +194,8 @@ The container also includes a health check for the Gradio HTTP process, so a
 reachable UI can be separated from later model-inference failures.
 Gradio is launched with detailed error display enabled, while the manifest and
 container logs remain the authoritative diagnostic record.
+Failed requests also leave a redacted failure manifest with the failing stage,
+backend, runtime, input hashes, and exception details for reproducible diagnosis.
 The Diagnostics panel checks the optional DA3 package and the expected
 `depth_anything_3.api.DepthAnything3` symbol separately, so an installed but
 incompatible DA3 package is visible before model inference.