* fix: builder with_* methods take T instead of Option<T>
* fix: emit conditional builder calls for optional fields in macros
* fix: convert with_task, with_stop_reason, with_logger, with_content to proper builders
* fix: update test callers for new builder signatures
* fix: simplify make_task helper and remove unused import
* fix: update sampling_stdio example for new with_stop_reason signature
* fix: make annotations and execution Option<Expr> consistent with other fields
* fix: remove unused none_expr import
* feat: implement SEP-1319 Decouple Request Payload from RPC Methods
* test: update tests
* fix: update handler trait methods to use new types
* fix: update examples
* fix: correct deprecation version
* fix: update wrapper macros to use new *Params type names