Response leak in SSE handlers

I found a resource leak in the streamable HTTP client. When SSE streaming fails with an exception, the HTTP response isn't closed.

Location:
src/mcp/client/streamable_http.py:

• _handle_sse_response (line 336)
• _handle_resumption_request (line 251)

The Issue:
python
async def _handle_sse_response(self, response: httpx.Response, ...):
try:
event_source = EventSource(response)
async for sse in event_source.aiter_sse():
if is_complete:
await response.aclose() # Only closed here
break
except Exception as e:
await ctx.read_stream_writer.send(e)
# response leaked!

If the SSE iteration raises an exception (malformed JSON, network error, etc.), the response is never closed.

Impact:
Connection pool gets exhausted in long-running clients, eventually causing new requests to hang or fail.

Fix:
try:
...
except Exception as e:
...
finally:
await response.aclose()

Both methods need this fix.

Env:
Python SDK version: 1.1.2 (or main branch)
Python: 3.12
Transport: StreamableHTTP

Đọc src/mcp/client/streamable_http.py, tập trung vào _handle_sse_response và _handle_resumption_request. Theo dõi cách mỗi phương thức xử lý việc lặp SSE và các ngoại lệ, sau đó xác minh rằng cả hai nhánh đều đóng HTTP response sau các lỗi cũng như sau khi hoàn tất bình thường.