v0.11.0

Added

• Support sampling/createMessage per MCP specification (#282)
• Support completion/complete per MCP specification (#289)

Fixed

• Support POST response SSE streams for server-to-client messages (#294)
• Return protocol errors for invalid arguments and server errors (#285)
• Fix client methods silently swallowing JSON-RPC error responses (#281)
• Close streams outside mutex in session cleanup (#291)