fix-technical-seolisted

# Fix technical SEO This skill covers the `technical-seo`, `on-page`, `security`, `performance` and `accessibility` findings; for GEO/AI-visibility artifacts (robots.txt, llms.txt, `.well-known/ai.json`, JSON-LD, sitemap wiring, IndexNow) use the `geo-implement` skill instead. Work from the audit report (run the `geo-audit` skill first). Fix `fail`s before `warn`s, and biggest lost points first. ## Per-check fixes — technical-seo - **canonical / canonical-resolves**: `<link rel="canonical" href="...">` with the absolute preferred URL on every page (self-referencing); the canonical target must return 200 directly, not redirect. - **www-consolidation**: pick one host (www or apex) and 301 the other to it — a single hop, one canonical origin everywhere (canonicals, sitemap, links). - **trailing-slash**: pick one style, 301 the other, consistently. - **redirect-chains / redirect-hygiene / https**: serve over HTTPS with at most one 301 hop; update internal links to point at final URLs. - **soft-404 / custom-404**: unknown URLs must return a real 404 status (not 200), ideally with a helpful custom page. - **broken-internal-links**: fix or remove every internal `<a href>` that returns >= 400; the audit message lists the dead paths. - **sitemap-lastmod / sitemap-urls-valid / sitemap-orphans**: real `lastmod` dates (not all identical/today), only canonical 200 URLs in the sitemap, and every important page reachable from both sitemap and internal links. - **meta-robo