docs/FEM_ARCHITECTURE.md

FEM Architecture - Vendor-Only Implementation

20-Step Empirical Testing & Build Plan

See full architecture document committed separately.

Vendor Stack

• scikit-fem: FE assembly
• pygmsh: Mesh generation
• meshio: I/O
• scipy.sparse: Linear algebra
• sympy: Symbolic math
• networkx: Topology
• pydantic: Validation

All code MUST use vendor APIs exclusively.