Michael Bolin c9ef7eff00 Resolve outbound proxy routes explicitly (#34435) ...

## Why

System proxy discovery can block, and delegating fallback to each transport can repeat discovery or apply inconsistent environment proxy behavior.

## What changed

- Resolve unavailable system proxy decisions to an explicit environment proxy or direct route, including `NO_PROXY` settings and WebSocket-specific fallbacks.
- Add asynchronous system proxy resolution that uses cached decisions first and serializes blocking platform lookups on Windows and macOS.
- Preserve `NO_PROXY` handling for WebSocket connections, including HTTP and HTTPS proxies, and hash proxy cache keys on every platform.

## Testing

- Add coverage for explicit environment fallback, cached asynchronous resolution, and proxied or bypassed WebSocket connections.

GitOrigin-RevId: 3b7cf170dcfe639eec53c3c1514f92bfcf13e7e9

2026-07-21 00:33:04 +00:00

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src

Resolve outbound proxy routes explicitly (#34435)

2026-07-21 00:33:04 +00:00

BUILD.bazel

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Cargo.toml

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