## Summary

The Bedrock Converse API supports `citations` and `context` fields on `DocumentBlock` (used when passing PDFs/documents to Claude models via Bedrock). These fields are not currently forwarded when converting Anthropic-style document content blocks to Bedrock format.

## Current behaviour

When a document content block includes `citations: {enabled: true}` or a `context` field, these are silently dropped during conversion in `BedrockConverseMessagesProcessor._process_document_message()`:

```python return BedrockContentBlock( document=BedrockDocumentBlock( source=BedrockSourceBlock(bytes=data), format=doc_format, name=document_name, ) ) # citations and context fields from the input block are never forwarded ```

## Expected behaviour

- If the Anthropic-style block has `citations: {enabled: true}`, it should be forwarded to Bedrock's `DocumentBlock` as `CitationsConfig(enabled=True)` - If the block has a `context` field, it should be forwarded to `DocumentBlock.context`

## Also affected

`DocumentBlock` in `litellm/types/llms/bedrock.py` is missing `citations` and `context` fields — it needs `total=False` and those two optional fields add…