Bug: pi-ai stream_read_error is treated as non-retryable PI_AI_ERROR

[Krual-T]

Summary

On current master (99f6f02fec, the rc.7 merge), an OpenAI-compatible streaming provider can terminate a response with the normalized error text stream_read_error. dsh-llm-pi-ai currently falls through to PI_AI_ERROR, so the default LLM retry policy treats a transient mid-stream transport truncation as permanent and ends the turn without retrying.

I searched the current Discussions for stream_read_error, stream read error, pi-ai transport classification, and retry handling and did not find an existing report for this exact case.

Why this is a transport failure

The failure occurs after streaming has started but before a valid terminal response event. It is the same failure family as the truncation wordings the classifier already maps to TRANSPORT, such as a stream ending before or without its terminal event.

The distinction matters because the default retryable codes include TRANSPORT, but not the generic PI_AI_ERROR. Making all PI_AI_ERROR values retryable would be too broad; classifying this specific normalized wording is the narrower fix.

Suggested fix

In packages/llm/llm-pi-ai/src/stream.ts, recognize the common underscore, space, and hyphen variants:

if (/\bstream[_\s-]+read[_\s-]+error\b/i.test(message)) return 'TRANSPORT'

Suggested focused cases:

stream_read_error
stream read error
stream-read-error

This should stay beside the existing pre-terminal stream-truncation classifications rather than widening the catch-all retry policy.

Upstream limitation

The pi-ai path currently reduces the original caught error to message text before the Harness classifier sees it, so the adapter cannot reliably inspect the original code or cause. Text classification is therefore a compatibility workaround. If pi-ai later preserves structured error metadata, the durable fix would be to route on that metadata and retire the wording heuristic.

Validation

I have a local rc.7 implementation with focused classifier coverage for all three variants. The relevant test, typecheck, and build checks pass. Since this repository currently does not accept external pull requests, I am posting the minimal change here and can provide a patch in the format maintainers prefer.