PH-BC-001

Name: Boundary condition violation (relative or absolute mode)

Severity: error

Input modes: adapter+dump

Scope separation (read first): PH-BC-001 validates Dirichlet- type boundary trace behavior in the production rule; Neumann/flux semantics are outside the production validation scope for v1.0. The rule’s emitted quantity is ||field.values_on_boundary() − boundary_target|| — a discrete-L² comparison of Dirichlet-type trace extraction against a caller-supplied target, not a Neumann flux check. CITATION.md, README, and test docstrings do not imply broader rule coverage than V1 provides.

Dirichlet-trace violation metric: discrete-L² norm of u|_{∂Ω} − g|_{∂Ω} on the unit square, mode-branched on ||g|| (absolute for near-zero Dirichlet, relative otherwise). Threshold 0.01 relative (tri-state) / 1e-3 absolute (binary).