Adopt reusable CI standard + 300-line splits (#167)

ci: adopt estate reusable CI + split 300-line violations (v0.22.0)

Squash merge of PR #167 (claude/adopt-ci-20260616)
Head: dc5145cd92

Agent-Session: deploy-operator-2026-06-16

includes/core/class-keyword-extractor.php

@@ -0,0 +1,156 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * phpcs:ignore WordPress.Files.FileName.InvalidClassFileName -- class naming convention differs from WordPress standard
+ *
+ * Shared keyword-extraction utility for the scoring and dedup pipeline.
+ *
+ * Extracts meaningful lowercase tokens from free text by stripping stop-words.
+ * Used by both PRAutoBlogger_Idea_Scorer and PRAutoBlogger_Semantic_Dedup as the
+ * fallback path when embedding similarity is unavailable.
+ *
+ * What: Static utility; no state.
+ * Who triggers: PRAutoBlogger_Idea_Scorer, PRAutoBlogger_Semantic_Dedup.
+ * Dependencies: none.
+ *
+ * @see core/class-idea-scorer.php    -- Primary consumer (scoring pipeline).
+ * @see core/class-semantic-dedup.php -- Secondary consumer (embedding fallback).
+ */
+class PRAutoBlogger_Keyword_Extractor {
+
+	/**
+	 * Common English stop-words filtered out before keyword matching.
+	 *
+	 * @var string[]
+	 */
+	private const STOPWORDS = array(
+		'a',
+		'an',
+		'the',
+		'and',
+		'or',
+		'but',
+		'is',
+		'are',
+		'was',
+		'were',
+		'in',
+		'on',
+		'at',
+		'to',
+		'for',
+		'of',
+		'with',
+		'by',
+		'from',
+		'as',
+		'it',
+		'its',
+		'this',
+		'that',
+		'your',
+		'you',
+		'how',
+		'what',
+		'when',
+		'why',
+		'where',
+		'which',
+		'who',
+		'do',
+		'does',
+		'did',
+		'not',
+		'no',
+		'can',
+		'will',
+		'should',
+		'could',
+		'would',
+		'may',
+		'might',
+		'have',
+		'has',
+		'had',
+		'be',
+		'been',
+		'being',
+		'about',
+		'into',
+		'through',
+		'during',
+		'before',
+		'after',
+		'above',
+		'below',
+		'between',
+		'same',
+		'up',
+		'down',
+		'out',
+		'off',
+		'over',
+		'under',
+		'again',
+		'then',
+		'here',
+		'there',
+		'all',
+		'each',
+		'every',
+		'both',
+		'few',
+		'more',
+		'most',
+		'other',
+		'some',
+		'such',
+		'than',
+		'too',
+		'very',
+		'just',
+		'also',
+		'only',
+		'own',
+		'so',
+		'if',
+		'while',
+		'because',
+		'until',
+		'vs',
+		'versus',
+		'guide',
+		'complete',
+		'ultimate',
+		'best',
+		'top',
+		'new',
+		'first',
+		'need',
+		'know',
+		'everything',
+	);
+
+	/**
+	 * Extract meaningful keywords from text.
+	 *
+	 * Lowercases input, splits on non-alphanumeric characters, filters
+	 * stop-words and single-character tokens, and de-duplicates.
+	 *
+	 * @param string $text Input text.
+	 * @return string[] Unique lowercase keyword tokens.
+	 */
+	public static function extract( string $text ): array {
+		$text  = strtolower( $text );
+		$words = preg_split( '/[^a-z0-9-]+/', $text, -1, PREG_SPLIT_NO_EMPTY );
+		$words = array_filter(
+			$words,
+			static function ( string $w ): bool {
+				return strlen( $w ) >= 2 && ! in_array( $w, self::STOPWORDS, true );
+			}
+		);
+
+		return array_values( array_unique( $words ) );
+	}
+}