fix: retry on all TransportError subclasses (ReadError, WriteError, etc.)

[fxdgear]

Summary

• Replaces individual except blocks for ConnectError, RemoteProtocolError, and TimeoutException with a single catch for their parent class httpx.TransportError
• This covers ReadError (TCP connection reset mid-response with empty message), WriteError, and all other transport-level failures
• Previously, ReadError fell through to the catch-all Exception handler and was wrapped as PermanentError, failing immediately without retry

Context

Follow-up to #332. After deploying the RemoteProtocolError fix, we observed httpx.ReadError (empty message) failures when api pods crashed mid-response. The TCP connection was reset during the response read phase, which httpx classifies as ReadError rather than RemoteProtocolError.

The httpx exception hierarchy:

TransportError
├── ConnectError          (was retried)
├── RemoteProtocolError   (was retried since #332)
├── ReadError             (was NOT retried — now fixed)
├── WriteError            (was NOT retried — now fixed)
├── PoolTimeout           (was NOT retried — now fixed)
└── ...
TimeoutException          (was retried, subclass of TransportError)
├── ConnectTimeout
├── ReadTimeout
├── WriteTimeout
└── PoolTimeout

Catching TransportError is the correct level — all transport errors are transient and should be retried when retry_connection_errors=True.

Test plan

• Parametrized tests for all TransportError subclasses (sync + async)
• Each subclass retried when retry_connection_errors=True
• Each subclass raises immediately when retry_connection_errors=False

🤖 Generated with Claude Code

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Note

Medium Risk
Expands which network failures are treated as retryable, which can change error/latency behavior for callers and potentially mask persistent transport issues until backoff is exhausted.

Overview
Broadened retry handling for transport failures. The retry wrapper now catches httpx.TransportError in both sync and async paths, so additional transport-level errors (e.g. ReadError, WriteError, and timeout subclasses) are retried when retry_connection_errors=True instead of being treated as permanent.

Tests were updated to parameterize across multiple TransportError subclasses for both sync and async retry behavior, and the package version/release notes were bumped to 0.42.12.

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