Function generate_r6_r_wrapper 

pub fn generate_r6_r_wrapper(parsed_impl: &ParsedImpl) -> String

Generates the complete R wrapper string for an R6-style class.

Produces an R6::R6Class(...) definition that includes:

• initialize method: calls the Rust new constructor, or accepts a pre-made .ptr when static methods return Self (factory pattern)
• Public methods: one R function per &self/&mut self instance method
• Private methods: methods marked with #[miniextendr(private)]
• Active bindings: getter/setter properties via #[miniextendr(r6(prop = "..."))]
• Private .ptr field: holds the ExternalPtr to the Rust struct
• Finalizer: optional destructor called when the R6 object is garbage-collected
• Deep clone: optional custom clone logic via #[miniextendr(r6(deep_clone))]
• Static methods: emitted as ClassName$method_name <- function(...) outside the class
• Class options: lock_objects, lock_class, cloneable, portable, inherit

Also generates roxygen2 documentation blocks for the class, its methods, and active bindings.