feat: add humanizer-pl skill (Polish signs of AI writing + humanizer)

[odwrotnie]

What

A Polish-language companion to the existing humanizer skill: skills/humanizer-pl/.

Polish AI text has tells that an English-oriented humanizer misses — English punctuation calques (em dashes instead of the Polish en dash, "English" instead of „Polish" quotation marks, commas after sentence-initial adverbials), syntactic calques (zaadresować problem, dedykowany dla, wydaje się być), and a distinct set of overused phrases (w dzisiejszym dynamicznie zmieniającym się świecie, warto zauważyć, że, kluczowy, podsumowując).

Contents

• signs-of-ai-writing-pl.md — a comprehensive, sourced field guide to AI-writing markers in Polish, structured after Wikipedia's Signs of AI writing (like writing-clearly-and-concisely/signs-of-ai-writing.md in this repo) but researched from Polish-language sources:
  • Polish academic research: ChatGPT error typology in Polish essays (LingVaria 2024), the PolEval 2025 "Śmigiel" machine-generated-text detection shared task, the CEAID multilingual detection benchmark, stylometry studies, the national anti-plagiarism system (JSA) methodology;
  • Polish Wikipedia community practice: fabricated references as the top marker, utm_source=chatgpt.com trails, Markdown artifacts in wikitext, bulk access-dates;
  • ~130 documented Polish phrases from SEO/copywriting phrase scanners and detector docs, each cross-checked across independent sources;
  • Polish typography norms (PWN) vs. LLM behavior: dash, quotes, comma calques, Title Case;
  • per-model signatures (ChatGPT eras, Claude, Gemini, DeepSeek, Polish Bielik/PLLuM) with marker "expiry dates";
  • a machine-translation vs. native-generation distinction (4 text profiles) — protecting human authors whose text went through DeepL from false accusations;
  • an "ineffective indicators" section (detector false-positive rates are >2× higher for Polish than English per vendor data).
• SKILL.md — editor instructions that strip these artifacts from Polish text and normalize Polish typography, with before/after examples; flags unverifiable claims as [DO WERYFIKACJI] instead of paraphrasing potential hallucinations.
• README.md, marketplace.json entry (utilities, keywords incl. polish), built dist/ plugin (python3 scripts/build_plugins.py run).

Notes

• The guide document is in Polish (its audience edits Polish text); SKILL frontmatter description and README are in English per repo conventions.
• Structure and universal markers adapted from Wikipedia's Signs of AI writing (CC BY-SA 4.0, attributed in the document); approach modeled on the humanizer skill.

🤖 Generated with Claude Code