MBSD Core v0.1.0 - Week 1 Core

Changelog

v0.1.0 - Week 1 Core

Initial public core release candidate.

• Add installable mbsd Python package.
• Add planar mechanism builder API through Mechanism.planar().
• Add planar rigid bodies, revolute joints, prismatic joints, coordinate drives,
  angular motors, kinematic solves, and constrained dynamics.
• Add examples for a driven slider, mass-spring mechanism, and slider-crank
  analysis.
• Add pytest smoke coverage for rotation matrices, slider tracking,
  mass-spring dynamics, and Jacobian finite-difference consistency.
• Keep longer-form documentation and website content outside the core package
  repository.
• Keep release planning outside the core package repository.
• Keep top-level exports intentionally small: Mechanism, Spring, and
  MechanismSolveError.
• Move Matplotlib out of core runtime dependencies and into the plot extra.
• Add explicit solver errors for singular, overconstrained, and accidental
  underconstrained solves.
• Add input validation and constraint-residual helpers.
• Add GitHub Actions CI for Python 3.10 through 3.13.
• Keep generated media, browser demo, CAD/rendering workflows, synthesis
  batches, and experimental 3D work out of the first core release.