v0.3.1 — stronger Layer B statistical-watermark rewrite

• rewrite_text.py default paraphrase now performs an explicit word-choice + syntax attack (clause order, connectors, transition words, sentence boundaries, function words) rather than a generic rewrite
• New --strength humanize: zero-shot "write like a human" pass targeting formulaic AI-style phrasing
• New --strength code: rewrites comments, docstrings, and string literals, and renames local identifiers while preserving behavior and public API names
• Structural pass now emits "natural, varied human prose" instead of AI-typical "clear professional style"
• New --temperature (default 0.9) for both Ollama and OpenAI-compatible backends
• New --candidates N: generates N rewrites and selects the most lexically diverged (bigram Jaccard distance) with a length-drift guard
• Stronger model hygiene: prefer local open-weight models and avoid any known-watermarked vendor, not just the suspected origin
• Residual-risk reporting now distinguishes short/highly predictable text (lower risk) from long, high-entropy prose (higher risk)
• Docs updated in SKILL.md, removal-matrix.md, and vendor-notes.md; tests cover new prompts, divergence scoring, and candidate selection