v0.9.0

Added

• MCP::Client::Stdio transport (#262)
• Progress notifications per MCP specification (#254)
• Automatic _meta parameter extraction support (#172)
• CORS and Accept wildcard support for browser-based MCP clients (#253)

Changed

• Use autoload to defer loading of unused subsystems (#255)
• Reduce release package size (#239)

Fixed

• Return 404 for invalid session ID in handle_regular_request (#257)
• Use mutex-protected session_exists? in handle_regular_request (#258)