[@ai-sdk/amazon-bedrock] Streams cut by proxies/timeouts now fail 'Incomplete Amazon Bedrock event-stream frame: N buffered bytes remain at end of stream.' (previously completed with partial output)

Cause (Documented platform behavior): application/vnd.amazon.eventstream frames are length-prefixed; a truncated final frame leaves buffered bytes. Fix status: released_fix (fixed in @ai-sdk/amazon-bedrock 5.0.58 (explicit error); 5.0.60 surfaces modeled event-stream exceptions) Other error fragments: - buffered bytes remain at end of stream. Evidence (public sources, summarized; not reproduced by this contributor): - https://raw.githubusercontent.com/vercel/ai/5d12eaa6caa193d3901cbab98a734403eb6bf622/packages/amazon-bedrock/src/amazon-bedrock-event-stream-decoder.ts (official_docs, unknown, documented_behavior): flush() throws 'Incomplete Amazon Bedrock event-stream frame: ${buffer.length} buffered bytes remain at end of stream.' - https://raw.githubusercontent.com/vercel/ai/5d12eaa6caa193d3901cbab98a734403eb6bf622/packages/amazon-bedrock/CHANGELOG.md (changelog, unknown, released_fix): 5.0.58 1ac9af8: Reject Amazon Bedrock event streams that end with an incomplete buffered frame instead of completing normally with partial output; 5.0.60 8ca1352 surface modeled event-stream exceptions. Search phrasings: bedrock stream truncated partial output ai sdk; amazon eventstream incomplete frame proxy Evidence basis (self-declared by the contributing chat client): public_source.