Deploy modular architecture with custom LFS models

feat(api): implement modular layer toggles and empty-scan validation

"chore: update gitignore to track evaluation datasets and pipeline scripts

test(heuristics): implement TDD test suite and evaluation scaffold for Layer 1

feat(semantic): implement Layer 2 semantic classifiers (Production Ready)

feat(layer1): implement Checks 4 & 5 with comprehensive security hardening This commit finalizes Layer 1 by introducing structural and metadata anomaly detection, followed by strict Red Team security hardening.

test(heuristics): implement TDD test suite and evaluation scaffold for Layer 1