Humanizer: remove AI writing patterns

Rewrite AI-sounding text so it reads like the writer, not a chatbot. Do not change what it says or make up details.

The patterns come from Wikipedia's "Signs of AI writing", maintained by WikiProject AI Cleanup.

Language routing

Detect the language of the text to humanize before applying the patterns:

• English text: use the patterns in references/patterns.md as written.
• Chinese text: read references/zh-adaptation.md first. It overrides the patterns that behave differently in Chinese (§14, §17, §19, §26), maps the others to their Chinese manifestations, and supplies the Chinese trigger vocabulary. Pattern numbers refer to the English statements in references/patterns.md.
• Mixed text: route each language span to its rule set.

The rewrite rules — keep every claim, never invent facts, match the voice — apply in every language.

What to do

When given text to humanize: