International / multilingual SEO audit focused on hreflang correctness. Detects and diagnoses the most common (and ranking-damaging) hreflang mistakes: missing or broken return tags, wrong language/region codes, missing x-default, self-referencing errors, conflicts between hreflang and canonical, and inconsistent signals across HTML head / HTTP headers / XML sitemap. Also reviews the broader international setup — URL structure (ccTLD vs subdirectory vs subdomain), language targeting, and geo signals. Use this skill whenever the user runs a multi-language or multi-region site and asks about hreflang, international SEO, multilingual SEO, the wrong-language page showing in search, duplicate-content across country versions, or "th/en page ranking in the wrong country". Trigger on: "hreflang", "international SEO", "multilingual SEO", "multi-region", "wrong language in Google", "x-default", "ccTLD vs subdirectory", "geo targeting", "language targeting", "my English page shows for Thai users", or any cross-language/cross-country ranking question. For full-site audits use /seo-analysis; for a single URL use /seo-page.