Stream errors can raise ValueError instead of GlobalRouterError

[saxon134]

error_from_stream_payload casts error.code to int for status_code. If a streaming error uses a symbolic code, such as {'error': {'message': 'bad', 'code': 'rate_limit_error'}}, this raises ValueError before GlobalRouterError is constructed. Keep status_code parsing separate from symbolic error codes so streaming callers consistently receive GlobalRouterError.

File: src/globalrouter/_errors.py

Line: 69

Severity: medium

Summary: valueerror on symbolic stream error code

[saxon134]

Coding Loop Plan

Refined Issue

Stream error frames with non-numeric error codes should be normalized into GlobalRouterError instead of leaking ValueError.

Implementation Plan

Implementation Plan

Add a focused regression test for SSE stream error frames whose error.code is not an integer, then make stream error normalization tolerate non-numeric codes. Keep the change scoped to stream error handling and avoid changing unrelated request/response behavior.

Development Tasks

1. Add regression tests for non-numeric stream error codes
   In tests/test_client.py, add focused tests that return an SSE data: frame containing an error object with a non-numeric code, such as "rate_limit_exceeded". Consume the stream and assert that GlobalRouterError is raised, not ValueError. Cover the sync chat stream path and, if practical using the existing pytest-asyncio setup, the async chat stream path because both use the same normalization helper through separate iterators.
   Files: tests/test_client.py
   Tests: python -m pytest tests/test_client.py -q -k "stream_error"

2. Make stream error status parsing safe
   Update error_from_stream_payload in src/globalrouter/_errors.py so it no longer calls int(...) directly on arbitrary error.code values. Add a small private helper or inline guarded conversion that returns the integer when the value is an int or numeric string, and falls back to 0 for non-numeric strings, missing values, booleans, or malformed error payloads. Preserve the existing GlobalRouterError fields and default message/code behavior unless the regression test requires otherwise.
   Files: src/globalrouter/_errors.py, tests/test_client.py
   Tests: python -m pytest tests/test_client.py -q -k "stream_error", python -m pytest tests/test_client.py -q