Function initialize_request 

pub fn initialize_request(id: i64, root_uri: Option<&str>) -> Value

initialize carrying the project root. Settings travel separately via didChangeConfiguration (and workspace/configuration answers).

workspaceFolders is mandatory, not decorative: a server that only sees rootUri falls back to a synthetic <default workspace root>, finds no files there, and then never re-analyzes an edited document — which is exactly what pyright logs when the root is missing.