build(deps): consolidate upgrades and fix compatibility

.github/workflows/ci.yml

@@ -69,7 +69,7 @@ jobs:
         -ra --durations=15 --junitxml=test-results/core.xml
         --cov=src/cbfkit/controllers --cov=src/cbfkit/optimization
         --cov=src/cbfkit/simulation --cov-report=xml
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v7
       if: always()
       with:
         name: core-python-${{ matrix.python-version }}
@@ -95,7 +95,7 @@ jobs:
     - run: >-
         uv run --no-sync pytest -m slow tests --ignore=tests/test_mujoco
         -ra --durations=15 --junitxml=test-results/examples.xml
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v7
       if: always()
       with:
         name: examples
@@ -131,7 +131,7 @@ jobs:
     - run: >-
         uv run --no-sync pytest tests/test_mujoco
         -ra --durations=15 --junitxml=test-results/mujoco.xml
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v7
       if: always()
       with:
         name: mujoco
@@ -237,7 +237,9 @@ jobs:
     - name: Verify wheel outside checkout
       run: |
         python -m venv "$RUNNER_TEMP/wheel-env"
-        "$RUNNER_TEMP/wheel-env/bin/pip" install dist/*.whl 'mujoco==3.11.0'
+        for wheel in dist/*.whl; do
+          "$RUNNER_TEMP/wheel-env/bin/pip" install "${wheel}[mujoco]"
+        done
         cd "$RUNNER_TEMP"
         "$RUNNER_TEMP/wheel-env/bin/python" "$GITHUB_WORKSPACE/scripts/check_installed_package.py" --mujoco
     - name: Verify sdist outside checkout

.github/workflows/integration.yml

@@ -55,7 +55,7 @@ jobs:
         uv run --no-sync pytest -ra --durations=15 --junitxml=test-results/g1.xml
         tests/test_mujoco/test_g1.py tests/test_mujoco/test_unitree_policy.py
         tests/test_mujoco/test_amo_policy.py tests/test_mujoco/test_groot_policy.py
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v7
       if: always()
       with:
         name: g1-integration-results
@@ -77,7 +77,7 @@ jobs:
         python -c 'import jax, torch; assert torch.cuda.is_available(); assert any(d.platform == "gpu" for d in jax.devices())'
         python -m pip install --no-deps -e .
     - run: python -m pytest -ra --junitxml=test-results/cuda.xml tests/test_wrappers/test_torch_safety_filter.py
-    - uses: actions/upload-artifact@v5
+    - uses: actions/upload-artifact@v7
       if: always()
       with:
         name: cuda-integration-results

pyproject.toml

@@ -74,7 +74,7 @@ cvxopt = [
 codegen = ["black>=23.12.1,<27.0"]
 # MuJoCo/MJX plant backend. mujoco and mujoco-mjx MUST be pinned to the same
 # version: mjx does not upper-bound mujoco and a skew crashes at import.
-mujoco = ["mujoco==3.11.0", "mujoco-mjx==3.11.0"]
+mujoco = ["mujoco==3.13.0", "mujoco-mjx==3.13.0"]
 
 # --- Convenience umbrella extras ---
 solvers = ["cbfkit[casadi]", "cbfkit[cvxopt]"]
@@ -95,12 +95,12 @@ all = [
 test = ["pytest>=8.0.2", "pytest-cov", "python-dotenv>=1.2.1"]
 test-all = ["cbfkit[test]", "cbfkit[all]"]
 quality = [
-    "mypy==1.18.2",
-    "ruff==0.14.6",
+    "mypy==2.3.1",
+    "ruff==0.16.8",
     "black==25.11.0",
     "isort==7.0.0",
     "pre-commit==4.3.0",
-    "types-PyYAML==6.0.12.20250915",
+    "types-PyYAML==6.0.12.20260906",
 ]
 build = ["build>=1.0", "twine>=5.0"]
 dev = [

src/cbfkit/optimization/quadratic_program/qp_solver_cvxopt.py

@@ -1,6 +1,8 @@
 """Quadratic program solver using the CVXOPT library."""
 
 import platform
+from importlib import import_module
+from types import ModuleType
 from typing import Any, Dict, Tuple, Union
 
 import jax.numpy as jnp
@@ -9,30 +11,25 @@
 
 from cbfkit.utils.user_types.solvers import QpSolution
 
-# Resolve cvxopt vs kvxopt once at import time (ARM vs x86)
-_cvxopt_available = True
-_cvxopt_error = None
+# Resolve the optional, platform-specific backend once at import time. Keep its
+# native matrix types behind the module boundary: cvxopt and kvxopt ship
+# different stubs even though both accept NumPy arrays at runtime.
+_cvxopt_backend: ModuleType | None = None
+_cvxopt_error: ImportError | None = None
 try:
     _mach = platform.machine().lower()
-    if "arm" in _mach or "aarch" in _mach:
-        from kvxopt import matrix as _matrix  # type: ignore[reportMissingImports]
-        from kvxopt import solvers as _solvers
-    else:
-        from cvxopt import matrix as _matrix
-        from cvxopt import solvers as _solvers
+    _cvxopt_backend = import_module("kvxopt" if "arm" in _mach or "aarch" in _mach else "cvxopt")
 except ImportError as _e:
-    _cvxopt_available = False
     _cvxopt_error = _e
-    _matrix = None  # type: ignore[assignment]
-    _solvers = None  # type: ignore[assignment]
 
 
-def _ensure_cvxopt():
-    if not _cvxopt_available:
+def _ensure_cvxopt() -> ModuleType:
+    if _cvxopt_backend is None:
         raise ImportError(
             "To use the cvxopt solver, please install the 'cvxopt' extra: "
             "pip install 'cbfkit[cvxopt]'"
         ) from _cvxopt_error
+    return _cvxopt_backend
 
 
 def solve(
@@ -57,8 +54,8 @@ def solve(
     -------
         (sol, success): Solution array and boolean success flag.
     """
-    _ensure_cvxopt()
-    matrix, solvers = _matrix, _solvers
+    backend = _ensure_cvxopt()
+    matrix, solvers = backend.matrix, backend.solvers
 
     # Use the cvxopt library to solve the quadratic program
     p_mat = matrix(np.array(p_mat, dtype=float))

tests/test_optimization/test_qp_solver_cvxopt_optional.py

@@ -0,0 +1,31 @@
+"""Missing platform-specific solvers should fail on use, not module import."""
+
+import importlib
+import platform
+import runpy
+from pathlib import Path
+
+import jax.numpy as jnp
+import pytest
+
+from cbfkit.optimization.quadratic_program import qp_solver_cvxopt
+
+
+@pytest.mark.parametrize(
+    "machine,package", [("arm64", "kvxopt"), ("aarch64", "kvxopt"), ("x86_64", "cvxopt")]
+)
+def test_missing_backend_reports_install_extra(monkeypatch, machine, package):
+    missing = ImportError(f"No module named {package}")
+
+    def unavailable(name):
+        assert name == package
+        raise missing
+
+    with monkeypatch.context() as patch:
+        patch.setattr(platform, "machine", lambda: machine)
+        patch.setattr(importlib, "import_module", unavailable)
+        namespace = runpy.run_path(str(Path(qp_solver_cvxopt.__file__)))
+
+    with pytest.raises(ImportError, match=r"pip install 'cbfkit\[cvxopt\]'") as exc:
+        namespace["solve"](jnp.eye(1), jnp.zeros(1))
+    assert exc.value.__cause__ is missing