## MODIFIED Requirements

### Requirement: Streaming Responses requests use a bounded retry budget
When a streaming `/v1/responses` request encounters upstream instability, the proxy MUST enforce a configurable total request budget across selection, token refresh, and upstream stream attempts. Each upstream stream attempt MUST clamp its connect timeout, idle timeout, and total request timeout to the remaining request budget.

#### Scenario: Remaining budget constrains all stream attempt timeouts
- **WHEN** account selection or token refresh leaves only part of the request budget available before a stream attempt starts
- **THEN** the proxy limits the upstream connect timeout, SSE idle timeout, and upstream request total timeout to that same remaining budget
- **AND** the client receives `response.failed` with `upstream_request_timeout` once that budget is exhausted instead of waiting through the full configured stream windows

#### Scenario: Forced refresh retry recomputes all attempt timeouts
- **WHEN** a first stream attempt fails with an authentication error that triggers a forced token refresh and retry
- **THEN** the proxy recomputes the remaining request budget after the refresh
- **AND** the retry attempt reapplies connect, idle, and total timeout limits from that recomputed budget
