sundials

Fetch and apply GitHub pull-request review comments locally, especially when the task includes reconciling new review traffic, following reply chains from specific reviewers/authors, and keeping a scratch notes file that maps comment IDs to fixes.

Generate nanobind C++ wrapper code for user-supplied callback functions in the sundials4py Python bindings. Use this skill whenever adding a new user-supplied function (callback) to any sundials4py submodule (arkode, cvodes, idas, kinsol, core/sundials), wrapping a C function-pointer-based API for Python, adding a `python` member to a SUNDIALS C struct that does not yet have one, or when a function cannot be autogenerated by litgen because it takes a function pointer argument. Also trigger when the user mentions "callback wrapper", "user_supplied_fn_caller", "BIND_ARKODE_CALLBACK", "BIND_CVODE_CALLBACK", "BIND_IDA_CALLBACK", "BIND_KINSOL_CALLBACK", or references any *_usersupplied.hpp or *_impl.h file in the context of Python bindings. If the user says something like "wrap this Set callback for Python", "add a new user function to cvodes", or "this object needs a python member for callbacks", this is the skill to use.

Build, install, and test SUNDIALS from source as an end user or as a SUNDIALS developer. Use when a request involves configuring CMake, selecting compilers/options (MPI, GPU backends, Fortran), building/installing, running CTest, enabling dev/unit tests, or troubleshooting common build/test issues.

Add a new SUNDIALS module (e.g., NVECTOR_*, SUNMATRIX_*, SUNLINSOL_*, SUNNONLINSOL_*, SUNMEMORY_*, or a new shared component) including source/header layout, CMake wiring, enable/disable options, exported CMake targets, installed component registration, and developer tests/examples/docs updates.