[huyengiang101086-spec]

Summary

Streaming and binary SDK requests currently decode failed HTTP responses in the requested success format. A 401 JSON response therefore produces a generic authentication message with a Readable body, while bytes/arraybuffer requests lose the structured error body in a Buffer.

Parse non-success responses through the existing JSON/text parser before mapping the HTTP error. Successful stream/binary decoding and retry policy remain unchanged. Real HTTP regressions cover 401 streaming, 422 bytes, 429 arraybuffer, the JSON-mode control, and malformed JSON error text. Request IDs and Retry-After metadata are preserved.

Fixes #43966

Validation

Windows, Node 24.21.0, repository-locked dependencies:

• Tests-first HTTP integration module: 4 failed, 5 passed on unchanged production; 9 passed with the fix.
• vp test --coverage from sdks/nodejs-client/: 116 passed.
• vp check sdks/nodejs-client from the root: format, lint and type checks passed.
• vp pack from sdks/nodejs-client/: passed.
• A local HTTP reproduction using the built public ChatClient.createChatMessage now preserves the server message and JSON body in both blocking and streaming modes.
• git diff --check: passed.

Checklist

• This change requires a documentation update, included: Dify Document (not required; restores existing error behavior across response modes)
• I understand that this PR may be closed in case there was no previous discussion or issues.
• I've verified the change and added or updated tests where meaningful regression risk justifies coverage.
• I've updated the documentation accordingly. (not required)
• I ran make lint && make type-check (backend) and vp staged (frontend). (SDK-only; scoped vp check passed instead)

From Codex