Complete Website Translation Integration

I need every public-facing element of my site available in multiple languages, not just a handful of strings. A compact language selector must appear in the site header so visitors can switch languages at any time. The scope covers all pages and their menu items; nothing a visitor can read or click should remain untranslated. Please handle the technical setup—whether that means configuring a translation plugin, wiring an API, or adding custom code—so the new language versions are generated, stored, and displayed correctly. SEO-friendly URLs, proper hreflang tags, and clean navigation between languages are important to me. I’m looking to launch this as soon as possible, so a swift, well-tested rollout is essential. Deliverables • Header language menu fully styled and functional • Complete translation of every existing page and its navigation items • Search-engine-friendly implementation with hreflang tags • Brief hand-off notes explaining how I can add or edit translations in the future