Eval v6: restore _fetch_first_rows

Eval v5: BitsAndBytesConfig for MoE 4-bit

Eval v4: --merged-repo, eos_token_id, deps without unsloth

Eval v4: Hermes JSON-string tools, merged-repo loader, eos_token_id

Eval v3: Hermes conv support + longest-block AST

Eval v2: clean rewrite with PEP 723 deps + inlined helpers

Eval: inline helpers (no cross-script import)

Add eval script (tool-call validity, code sanity, security MCQ)