BIT 4.2.1 is a patch release for BGSD diagnostic compatibility.
Fixes:
- Emits structured BIT validation diagnostics with the exact BGSD prefixes: BGSD_WARNING: and BGSD_INFO:.
- Keeps existing diagnostic metadata such as [code=...] and [key=...] so BGSD can parse and surface physical validation, key validation, type validation, default-size, and auto-size messages.
Verification:
- Package smoke compile passed.
- Focused diagnostics checks passed for test_key_validation and test_validation_flags.
- Raw OpenSCAD compile confirmed test_physical_validation emits BGSD_WARNING: physical validation messages.