tk-convert's tests/oracle.rs (huggingface/tokenizers) and the Makefile's ORACLE_RESOURCES already reference fixtures/models/siglip-base-patch16-224.json and fixtures/models/mistral-7b-v0.1.json, but neither file was ever pushed here -- both tests fail loudly on a fresh checkout. Adding the two tokenizer.json files straight from google/siglip-base-patch16-224 and mistralai/Mistral-7B-v0.1.
Add sentence-transformers all-MiniLM-L6-v2 and all-mpnet-base-v2 tokenizer.json fixtures (#11)
