seo: add visible FAQ section with FAQPage schema (6 keyword-targeted Q&As)

Targets high-volume search queries:
- netflix watch2gether / netflix watch in sync
- free teleparty alternative / teleparty alternative
- emby syncplay / jellyfin sync
- watch together extension browsers
- privacy-friendly watch party

Native <details> elements — no JS, Google-visible, Rich-Snippet eligible.
All 6 languages translated (EN/DE/FR/ES/PT-BR/RU).

website/locales/en.json

@@ -112,6 +112,21 @@
   "BOTTOM_SUBTITLE": "KoalaSync is 100% open source, ad-free and tracking-free. Audit our codebase on GitHub or install the browser extension directly.",
   "BOTTOM_MASCOT_ALT": "A cute koala holding a GitHub repository page next to the GitHub mascot Octocat",
   
+  "FAQ_TITLE": "Frequently Asked Questions",
+  "FAQ_SUBTITLE": "Everything you need to know about watching videos together in perfect sync.",
+  "FAQ_Q1": "Can I watch Netflix together in sync with friends?",
+  "FAQ_A1": "Yes! KoalaSync works on Netflix, YouTube, Twitch, Disney+, Amazon Prime Video, and practically any website with an HTML5 video player. Install the extension, create a room, share the invite link, and everyone watches in perfect sync — no lag, no desync.",
+  "FAQ_Q2": "Is KoalaSync a free alternative to Teleparty?",
+  "FAQ_A2": "100% free and open source under the MIT License. No premium tiers, no locked features, no ads — everything is included. Unlike Teleparty, KoalaSync's relay server is RAM-only with zero data collection or user accounts required.",
+  "FAQ_Q3": "Does KoalaSync work with Emby, Jellyfin and self-hosted media servers?",
+  "FAQ_A3": "Yes. KoalaSync detects any standard HTML5 video element, which means it works perfectly with Emby, Jellyfin, Plex, and any custom self-hosted streaming setup. You can also self-host the KoalaSync relay server via Docker for complete data sovereignty.",
+  "FAQ_Q4": "Which browsers and platforms support KoalaSync?",
+  "FAQ_A4": "Google Chrome, Mozilla Firefox, Microsoft Edge, Opera, Brave, and all Chromium-based browsers. Install it directly from the Chrome Web Store or Firefox Add-ons — no manual configuration needed.",
+  "FAQ_Q5": "Do all my friends need the extension installed?",
+  "FAQ_A5": "Yes, each participant needs KoalaSync installed — but there's no sign-up or account creation. Simply click the invitation link, install the extension if you haven't already, and you'll join the room automatically in seconds.",
+  "FAQ_Q6": "Is my data safe? Do you track or store what I watch?",
+  "FAQ_A6": "Not at all. KoalaSync's relay server is RAM-only — all session data is permanently deleted the moment you leave the room. There's no database, no logging, no analytics, and no user accounts. The entire codebase is open source and auditable on GitHub.",
+  
   "FOOTER_MIT": "Open source under the MIT License.",
   "FOOTER_RAM": "No data is stored on our servers. Pure RAM-based relay.",
   "FOOTER_LEGAL": "Legal Notice",