Add schema.py — DomainSchema, FieldSpec, FieldType definitions

Phase 2A: Core tokenizer library — schema, field tokenizers, composite builder, predefined schemas, 72 passing tests

Update README: add ADR reference, update documentation table and repo structure

Add ADR-001: Implementation framework decision with detailed roadmap

Update README with Nubank case study and expanded repo structure

Add Nubank nuFormer reverse-engineering analysis — full pipeline reconstruction

Add README with project overview and vision

Add comprehensive research report on domain-specific tokenization

initial commit