peptide-geo-monitor v0.1.0: internal AI-visibility dashboard (#1)

New internal plugin: weekly LLM probes of core peptides (Perplexity sonar + GPT/Gemini-search via OpenRouter/CF gateway) -> custom table -> wp-admin trendline + standings. Provider interface + cost ledger w/ hard $5/mo cap + collector/panel seam (AI-visibility only). v1 = AI-visibility only.

QA: APPROVE-WITH-P2-NOTES — qa-reviews/peptide-geo-monitor/2026-06-13-f488f4a966cbb9e771d3abc20daee3fa49074520.md (P2 follow-ups: ltrim www display bug, PHPCS mandatory, dead cache)

Agent-Session: geomonitor v0.1.0 merge

includes/providers/class-pgm-citation-detector.php

@@ -0,0 +1,80 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * Detects whether peptiderepo.com appears in a list of source domains.
+ *
+ * Centralises the citation-detection logic so both providers can share it
+ * without duplication.  Also parses raw citation arrays/URLs into a clean
+ * domain list.
+ *
+ * Who triggers: PGM_Perplexity_Provider, PGM_OpenRouter_Provider.
+ * Dependencies: None (pure PHP).
+ *
+ * @see CONTEXT.md — "cited", "our_position", "source_domains".
+ * @package PeptideGeoMonitor
+ */
+class PGM_Citation_Detector {
+
+	/**
+	 * Parse raw citation data from an API response into a clean domain list.
+	 *
+	 * Accepts either a flat array of URL strings or an array of objects with
+	 * a 'url' key (Perplexity style). Unknown shapes are skipped gracefully.
+	 *
+	 * @param array<mixed> $raw_citations Raw citations from the API response.
+	 *
+	 * @return string[] Lowercase domain names (e.g. ['peptiderepo.com', 'examine.com']).
+	 */
+	public function parse_domains( array $raw_citations ): array {
+		$domains = array();
+
+		foreach ( $raw_citations as $item ) {
+			$url = '';
+			if ( is_string( $item ) ) {
+				$url = $item;
+			} elseif ( is_array( $item ) && isset( $item['url'] ) && is_string( $item['url'] ) ) {
+				$url = $item['url'];
+			}
+
+			if ( '' === $url ) {
+				continue;
+			}
+
+			$host = (string) wp_parse_url( $url, PHP_URL_HOST );
+			if ( '' !== $host ) {
+				$domains[] = strtolower( ltrim( $host, 'www.' ) );
+			}
+		}
+
+		return array_values( array_unique( $domains ) );
+	}
+
+	/**
+	 * Detect whether PGM_TARGET_DOMAIN appears in a domain list.
+	 *
+	 * @param string[] $domains Parsed domain list from parse_domains().
+	 *
+	 * @return bool
+	 */
+	public function is_cited( array $domains ): bool {
+		return in_array( PGM_TARGET_DOMAIN, $domains, true );
+	}
+
+	/**
+	 * Find the 1-based position of PGM_TARGET_DOMAIN in a domain list.
+	 *
+	 * Returns null when the target domain is not found.
+	 *
+	 * @param string[] $domains Parsed domain list.
+	 *
+	 * @return int|null
+	 */
+	public function get_our_position( array $domains ): ?int {
+		$pos = array_search( PGM_TARGET_DOMAIN, $domains, true );
+		if ( false === $pos ) {
+			return null;
+		}
+		return (int) $pos + 1; // Convert 0-based index to 1-based position.
+	}
+}