Spam Text Classification

You are given:

• texts[n]: an array of text strings to classify
• spamWords[k]: an array of words considered spam indicators

Classify each text as "spam" or "not_spam" using these rules:

• A text is "spam" if it contains at least 2 occurrences of words that appear in spamWords.
• A text is "not_spam" if it contains fewer than 2 such occurrences.
• Matching is case-insensitive.
• Words are separated by single spaces (treat each token as a word).
• Each occurrence counts, including repeated spam words in the same text (for example, "paid paid" counts as 2).
• Only consider words that exactly match a spam word (no partial matches).

Return an array of length n, where the ith value is the label for texts[i].