Fix compile error: adapt to jieba-rs 0.10.1 Token API

[Copilot]

jieba-rs 0.10.1 changed cut, cut_all, and cut_for_search to return Vec<Token<'a>> instead of Vec<&'a str>. This breaks compilation on main.

• Extract .word from each Token in cut(), cut_all(), cut_for_search() before passing to Array::from_vec
• Fix CutTask::compute() to use t.word.to_string() on the new Token type

// Before (no longer compiles)
let cutted = self.0.cut(sentence, hmm);
Array::from_vec(env, cutted)

// After
let cutted: Vec<&str> = self.0.cut(sentence, hmm)
    .into_iter()
    .map(|t| t.word)
    .collect();
Array::from_vec(env, cutted)