fix: parse Bedrock event-stream framing for non-Claude models

.flake8

@@ -1,4 +1,5 @@
 [flake8]
 max-line-length = 88
 exclude = .git,.github,.chglog,__pycache__,docs,venv,env,mypy_cache
-max-complexity = 10
+max-complexity = 10
+extend-ignore = E203

README.md

@@ -542,6 +542,24 @@ For more detailed examples and integration patterns, check out:
 
 ---
 
+## Streaming
+
+The SDK auto-detects the response wire format from `Content-Type`:
+
+- `application/vnd.amazon.eventstream` — AWS Bedrock event-stream framing (used by `invoke-with-response-stream` and `converse-stream`). Frames are parsed via `botocore.eventstream`; Bedrock's `{"bytes": "<base64-json>"}` envelope is unwrapped automatically.
+- `text/event-stream` / `application/x-ndjson` — SSE (OpenAI, Anthropic direct, Gemini).
+
+Each route configures a `stream_response_path` (JSONPath) that extracts the per-chunk text from the model's native chunk schema. Common values:
+
+| Model family             | `stream_response_path`     |
+| ------------------------ | -------------------------- |
+| Anthropic Claude         | `delta.text`               |
+| Meta Llama (Bedrock)     | `generation`               |
+| Cohere Command (Bedrock) | `text`                     |
+| OpenAI chat              | `choices[0].delta.content` |
+
+If `stream_response_path` doesn't match a chunk, the SDK logs a single structured WARNING with the payload keys it saw — check that warning against the `ModelSpec` on the gateway.
+
 ## Type Hints & py.typed Marker
 
 This package includes a `py.typed` marker file, which indicates to type checkers (like `mypy`, `pyright`, `pylance`) that the package supports type checking. This allows IDEs and static analysis tools to provide better autocomplete, type checking, and refactoring support.