Improvements to testspeed

Support named CLI flags, physics overrides, and refactor global state.

  - **Named CLI Flags**: Replaced standard positional arguments with named flags (`--nstep`, `--nthread`, `--noisestd`, `--noiserate`, `--npoolthread`) and preserved Google-wide flags compatibility (via custom argv compacting and InitGoogle).
  - **Physics Option Overrides**: Added support for configuring loaded model settings directly from the command line (`--solver`, `--cone`, `--jacobian`, `--integrator`, `--iterations`, `--tolerance`, `--sleep_tolerance`, `--noslip_iterations`).
  - **Encapsulated Thread State**: Consolidated loose global variables and per-thread rollout statistics arrays into a single data structure, `RolloutRunner runner`, simplifying mutli-threaded data boundaries.
  - **Readable Physics Options Printing**: Logged configured non-default options dynamically prior to rollout. Enums and active bitmask flags (e.g. disableflags/enableflags) are decoded into friendly strings (e.g., `Sleep : Enabled`).
  - **Tests & Docs**: Added testspeed_test.sh running testspeed over dominos.xml to check all overrides, registered shell test target in BUILD and CMakeLists.txt, and updated samples.rst documentation.

PiperOrigin-RevId: 942285912
Change-Id: Idb966fadfa0ccba0f1862f9d62bf83458b61939a

doc/programming/samples.rst

@@ -21,34 +21,61 @@ the console. To simulate controlled dynamics instead of passive dynamics one can
 
 .. code-block:: Shell
 
-   testspeed modelfile [nstep nthread ctrlnoise npoolthread]
+   testspeed [options] model
 
-Where the command line arguments are
+Where the command-line options and arguments are
 
 .. list-table::
    :width: 95%
    :align: left
-   :widths: 1 1 5
+   :widths: 2 1 4
    :header-rows: 1
 
-   * - Argument
+   * - Option
      - Default
      - Meaning
-   * - ``modelfile``
+   * - ``model``
      - (required)
-     - path to model
-   * - ``nstep``
+     - path to model (positional argument)
+   * - ``--nstep=N``
      - 10000
      - number of steps per rollout
-   * - ``nthread``
+   * - ``--nthread=N``
      - 1
      - number of threads running parallel rollouts
-   * - ``ctrlnoise``
+   * - ``--noisestd=X``
      - 0.01
      - scale of pseudo-random noise injected into actuators
-   * - ``npoolthread``
-     - 1
+   * - ``--noiserate=X``
+     - 0.1
+     - rate of convergence to ctrl keyframe/midpoint
+   * - ``--npoolthread=N``
+     - 0
      - number of threads in engine-internal threadpool
+   * - ``--solver=S``
+     - Newton
+     - override constraint solver algorithm (PGS, CG, Newton)
+   * - ``--cone=C``
+     - Pyramidal
+     - override friction cone type (Pyramidal, Elliptic)
+   * - ``--jacobian=J``
+     - Auto
+     - override constraint Jacobian type (Dense, Sparse, Auto)
+   * - ``--integrator=I``
+     - Euler
+     - override integration mode (Euler, RK4, Implicit, ImplicitFast)
+   * - ``--iterations=N``
+     - 100
+     - override solver iterations limit
+   * - ``--tolerance=X``
+     - 1e-8
+     - override solver convergence tolerance
+   * - ``--sleep_tolerance=X``
+     - 1e-4
+     - override sleep tolerance
+   * - ``--noslip_iterations=N``
+     - 0
+     - override noslip solver iterations limit
 
 **Notes:**
 
@@ -58,8 +85,10 @@ Where the command line arguments are
   logical cores.
 - By default, the simulation starts from the model reference configuration with zero velocities. However, if a
   keyframe named "test" is present in the model, it is used as the initial state.
-- The ``ctrlnoise`` argument prevents models from settling into a static state where, due to warmstarts, one can
-  measure artificially faster simulation.
+- The physics option override flags (such as ``--solver``) only override the model settings if they are explicitly
+  specified on the command line; otherwise, the model options configured in the XML file are preserved.
+- The control noise arguments (``noisestd`` and ``noiserate``) prevent models from settling into a static state where,
+  due to warmstarts, one can measure artificially faster simulation.
 - When ``npoolthread > 1`` is specified, an engine-internal thread pool is created with the specified number of
   threads, to speed up simulation of large scenes. Note that while it is possible to use both ``nthread`` and
   ``npoolthread``, the scenarios for which one would want these different types of multithreading are usually mutually