* fix: filter out messages with empty content arrays for Bedrock API
The convertToModelMessages function from AI SDK can produce messages with
empty content arrays when assistant messages have only tool call parts or
when tool results aren't properly converted. Bedrock API rejects these with
400 errors. This fix filters out invalid messages before sending to the API.
* fix: add diagnostic logging for empty message content
Added logging to capture the original UI message structure when empty content
is detected after conversion. This helps debug the root cause while the
filter provides a safety net for Bedrock API compatibility.
* fix: correct anthropic beta header config for fine-grained tool streaming
- Use bedrock.anthropicBeta for Bedrock provider (not additionalModelRequestFields)
- Use top-level headers for direct Anthropic API
- Update @ai-sdk/amazon-bedrock to 3.0.62
- Add headers support to ModelConfig interface
* fix: update @ai-sdk/amazon-bedrock to 3.0.62 for tool streaming support
* feat: use pull_request_target to support fork PR reviews
* feat: expand PR review scope to catch more issues
- Add categories for scope creep, suspicious .gitignore additions, UI inconsistencies
- Change from 'be very selective' to 'report ALL issues found'
- Simplify DO NOT comment list to allow more actionable feedback