Address Kamino solver configuration feedback

Document the public base configuration, keep its test coverage extensible, and provide a clear error when it is used without a concrete dynamics solver.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: Ruben Grandia

docs/source/api/lab_newton/isaaclab_newton.physics.rst

@@ -29,6 +29,7 @@
     KaminoMaterialsCfg
     KaminoPADMMCfg
     KaminoPADMMSolverCfg
+    KaminoSolverCfgBase
     MPMSolverCfg
     HydroelasticSDFCfg
 
@@ -105,6 +106,11 @@ Physics Configuration
   :show-inheritance:
   :exclude-members: __init__
 
+.. autoclass:: KaminoSolverCfgBase
+  :members:
+  :show-inheritance:
+  :exclude-members: __init__
+
 .. autoclass:: KaminoPADMMSolverCfg
   :members:
   :show-inheritance:

docs/source/overview/core-concepts/physical-backends/newton/kamino-solver.rst

@@ -180,9 +180,8 @@ Kamino Solver Parameters
 ------------------------
 
 The following fields are shared by
-:class:`~isaaclab_newton.physics.KaminoPADMMSolverCfg` and
-:class:`~isaaclab_newton.physics.KaminoDVISolverCfg`. They are grouped by the part
-of the solver they affect.
+:class:`~isaaclab_newton.physics.KaminoSolverCfgBase`. They are grouped by the part of
+the solver they affect.
 
 Core Integration
 ^^^^^^^^^^^^^^^^

source/isaaclab_newton/isaaclab_newton/physics/kamino_manager_cfg.py

@@ -329,7 +329,9 @@ class KaminoSolverCfgBase(NewtonSolverCfg):
 
     def _get_dynamics_solver_config(self) -> tuple[Literal["padmm", "dvi"], dict[str, Any]]:
         """Return the selected Newton solver name and its configuration keyword arguments."""
-        raise NotImplementedError
+        raise NotImplementedError(
+            f"{type(self).__name__} is a base configuration. Use KaminoPADMMSolverCfg or KaminoDVISolverCfg."
+        )
 
     def to_solver_config(self) -> SolverKamino.Config:
         """Build a :class:`SolverKamino.Config` from this configuration.

source/isaaclab_newton/test/physics/test_newton_manager_abstraction.py

@@ -38,6 +38,7 @@
     KaminoDynamicsCfg,
     KaminoPADMMCfg,
     KaminoPADMMSolverCfg,
+    KaminoSolverCfgBase,
     MJWarpSolverCfg,
     MPMSolverCfg,
     NewtonCfg,
@@ -163,6 +164,15 @@ def test_newton_cfg_post_init_propagates_class_type(
     assert cfg.class_type.__name__ == expected_manager.__name__
 
 
+def test_kamino_solver_cfg_base_requires_concrete_configuration():
+    """The public Kamino base config should direct users to a concrete solver config."""
+    with pytest.raises(
+        NotImplementedError,
+        match="KaminoSolverCfgBase is a base configuration. Use KaminoPADMMSolverCfg or KaminoDVISolverCfg.",
+    ):
+        KaminoSolverCfgBase().to_solver_config()
+
+
 @pytest.mark.parametrize(
     "num_substeps, collision_decimation, should_warn",
     [
@@ -1000,7 +1010,7 @@ def test_initialize_solver_populates_canonical_state(
             # something to work with.
             body = builder.add_body(mass=1.0)
             builder.add_joint_revolute(parent=-1, child=body, axis=(0, 0, 1))
-            if isinstance(solver_cfg, (KaminoPADMMSolverCfg, KaminoDVISolverCfg)) and solver_cfg.use_collision_detector:
+            if isinstance(solver_cfg, KaminoSolverCfgBase) and solver_cfg.use_collision_detector:
                 builder.add_shape_sphere(body=body, radius=0.05)
                 builder.add_ground_plane()
         NewtonManager.set_builder(builder)