Finishing the refactor...

[dellaert]

Now Kinematics/Mechanics/Statics/Dynamics work in the same way.

Next up after this PR: move all the factors (and tests), and try to remove all direct uses of factors outside the kinematics/Mmechanics/statics/dynamics folders, to keep the code base modular.

[Copilot]

Pull request overview

This PR completes a refactor to make Kinematics, Mechanics, Statics, and the new Dynamics factor-builders follow the same context pattern (Slice / Interval / Phase), while reducing duplication in DynamicsGraph and aligning parameter hierarchies.

Changes:

• Introduces a new Mechanics layer (and MechanicsParameters) to centralize shared wrench/torque factor groups for statics/dynamics.
• Introduces a new Dynamics factor builder (with DynamicsParameters) and delegates slice/interval/phase dynamics assembly out of DynamicsGraph.
• Adds ContextUtils helpers to assemble per-slice factor graphs/values across interval-like contexts; updates wrappers and adds an architecture plan doc.

Reviewed changes

Copilot reviewed 28 out of 28 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
gtdynamics/utils/ContextUtils.h	Adds utilities to iterate contexts and accumulate per-slice graphs/values.
gtdynamics/statics/StaticsSlice.cpp	Converts slice statics API to explicit template specializations; removes direct factor includes.
gtdynamics/statics/StaticsInterval.cpp	Implements interval statics via collectFactors/collectValues.
gtdynamics/statics/StaticsPhase.cpp	Implements phase statics by delegating to interval.
gtdynamics/statics/Statics.h	Makes Statics compose shared mechanics factor groups via Mechanics; updates parameter inheritance.
gtdynamics/mechanics/Mechanics.h	Introduces shared mechanics factor builder interface (templated-by-context).
gtdynamics/mechanics/MechanicsParameters.h	Introduces shared parameter bundle for mechanics-level factor groups.
gtdynamics/mechanics/MechanicsSlice.cpp	Implements mechanics factor groups for a single slice.
gtdynamics/mechanics/MechanicsInterval.cpp	Implements mechanics factor groups across an interval by collecting slices.
gtdynamics/mechanics/MechanicsPhase.cpp	Implements mechanics factor groups across a phase by delegating to interval.
gtdynamics/mechanics/CMakeLists.txt	Placeholder note (sources pulled via top-level globbing).
gtdynamics/kinematics/Kinematics.h	Expands documentation and context-template API surface for q/v factor helpers.
gtdynamics/kinematics/KinematicsSlice.cpp	Moves slice q/v factor implementations to explicit template specializations.
gtdynamics/kinematics/KinematicsInterval.cpp	Refactors interval implementations to use collectFactors/collectValues; adds q/v interval specializations.
gtdynamics/kinematics/KinematicsPhase.cpp	Adds q/v phase specializations delegating to interval.
gtdynamics/dynamics/Dynamics.h	Introduces Dynamics factor builder class with context-templated API.
gtdynamics/dynamics/DynamicsParameters.h	Introduces DynamicsParameters (inherits MechanicsParameters) and migrates dynamics noise models.
gtdynamics/dynamics/DynamicsSlice.cpp	Implements slice acceleration factors and dynamic-only wrench/contact factors.
gtdynamics/dynamics/DynamicsInterval.cpp	Implements interval dynamics via per-slice collection.
gtdynamics/dynamics/DynamicsPhase.cpp	Implements phase dynamics by delegating to interval.
gtdynamics/dynamics/MechanicsParameters.h	Adds backwards-compatible include for moved mechanics parameters.
gtdynamics/dynamics/OptimizerSetting.h	Changes inheritance to include DynamicsParameters; removes in-class factor model members.
gtdynamics/dynamics/OptimizerSetting.cpp	Updates default ctor to use DynamicsParameters() instead of initializing all models locally.
gtdynamics/dynamics/DynamicsGraph.h	Stores Mechanics and Dynamics members; adds configuredSettings helper.
gtdynamics/dynamics/DynamicsGraph.cpp	Delegates aFactors/dynamics-only factor assembly to Dynamics and shared groups to Mechanics.
gtdynamics/CMakeLists.txt	Adds mechanics directory to library source subdirs.
gtdynamics.i	Updates wrapper exposure for moved/added parameter types and new Dynamics builder.
doc/kinodynamics-architecture-refactor-plan.md	Adds a detailed phased refactor plan and architecture guidance.