## Why
Timeout tests can avoid waiting for real deadlines by advancing Tokio's clock, but automatic advancement can expire requests before they reach the mock server.
## What changed
Pause Tokio time in the stalled-header sampling and model catalog deadline tests. Keep polling until the mock server receives each request, then explicitly advance past the relevant timeout. Add bounded wall-clock waits and fail if a request completes before reaching the server.
Preserve assertions for sampling retry exhaustion, connection permit recovery, and the catalog's `RequestTimeout` error.
GitOrigin-RevId: 252be25d75d73c713a4b8ccac1ff20ad820df556
## Why
Providers configured with `gateway_oauth` need gateway credentials alongside primary authentication for inference and model discovery.
## What changed
- Attach gateway tokens through the configured header or cookie while preserving primary authentication, including WebSocket handshake headers.
- Share gateway credential managers across matching provider instances and model discovery so they observe refreshed tokens.
- Reject authentication on gateway setup or token failures, invalid token values, and conflicting auth headers. Mark gateway headers sensitive and avoid exposing issuer error details.
- Include gateway OAuth configuration in model catalog cache identity to prevent reuse across different gateway configurations.
## Testing
Add provider and core integration tests covering combined credentials, header and cookie delivery, token refresh, shared credential state, cache isolation, and request blocking on gateway token or HTTP client initialization failures.
GitOrigin-RevId: cb74125cf7e87660967d49edacf14646cf0b99c4
## Why
Model catalog decode errors can include the full response body and payload values from deserialization errors. Catalog request deadlines also report a generic timeout instead of a request timeout.
## What changed
- Report only the JSON error category, line, column, and response byte count when model catalog decoding fails.
- Return `CodexErr::RequestTimeout` when the model catalog refresh deadline expires.
## Testing
Add regression tests for invalid response shapes, large payload values, malformed and truncated JSON, and a delayed catalog response that must return `RequestTimeout`.
GitOrigin-RevId: 6fe5111a3e3b113d79942b3c213f8e94d773eb5a
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