When `allowSyntheticToolResults` is false (OpenAI, OpenRouter, and most
third-party providers), the guard never cleared its pending tool call map
when a user message arrived during in-flight tool execution. This left
orphaned tool_use blocks in the transcript with no matching tool_result,
causing the provider API to reject all subsequent requests with 400 errors
and permanently breaking the session.
The fix removes the `allowSyntheticToolResults` gate around the flush
calls. `flushPendingToolResults()` already handles both cases correctly:
it only inserts synthetic results when allowed, and always clears the
pending map. The gate was preventing the map from being cleared at all
for providers that disable synthetic results.
Fixes#32098
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
11aa18b525