feat: add per-platform SEO landing pages (/youtube-downloader, etc.)

Create a dedicated, dynamically-routed page for each of 15 curated
platforms (YouTube, TikTok, Instagram, Facebook, X, Reddit, Pinterest,
Vimeo, SoundCloud, Twitch, Dailymotion, LinkedIn, Tumblr, VK, Snapchat)
under /[locale]/[slug], with a tailored hero, an example URL matched
to the platform, a unique "about" paragraph, and a mix of
platform-specific and shared FAQ items, all translated across
en/fr/es/it. Unknown slugs 404.

Kept the scope to a curated list rather than all 1380 yt-dlp
extractors to avoid thin/duplicate "doorway page" content that search
engines penalize.

The homepage's platform badges and the "+1000 sites" links now point
to these pages, extracted the FAQ accordion markup into a shared
FaqAccordion component reused by both the homepage FAQ and the new
platform pages.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/lib/downloader-platforms.ts

@@ -0,0 +1,28 @@
+export type DownloaderPlatform = {
+  id: string
+  slug: string
+  name: string
+  exampleUrl: string
+}
+
+export const DOWNLOADER_PLATFORMS: DownloaderPlatform[] = [
+  { id: 'youtube', slug: 'youtube-downloader', name: 'YouTube', exampleUrl: 'https://www.youtube.com/watch?v=dQw4w9WgXcQ' },
+  { id: 'tiktok', slug: 'tiktok-downloader', name: 'TikTok', exampleUrl: 'https://www.tiktok.com/@username/video/1234567890123456789' },
+  { id: 'instagram', slug: 'instagram-downloader', name: 'Instagram', exampleUrl: 'https://www.instagram.com/reel/Cxxxxxxxxxx/' },
+  { id: 'facebook', slug: 'facebook-downloader', name: 'Facebook', exampleUrl: 'https://www.facebook.com/watch/?v=1234567890123456' },
+  { id: 'twitter', slug: 'twitter-downloader', name: 'X (Twitter)', exampleUrl: 'https://x.com/username/status/1234567890123456789' },
+  { id: 'reddit', slug: 'reddit-downloader', name: 'Reddit', exampleUrl: 'https://www.reddit.com/r/videos/comments/abc123/example_post/' },
+  { id: 'pinterest', slug: 'pinterest-downloader', name: 'Pinterest', exampleUrl: 'https://www.pinterest.com/pin/1234567890123456789/' },
+  { id: 'vimeo', slug: 'vimeo-downloader', name: 'Vimeo', exampleUrl: 'https://vimeo.com/123456789' },
+  { id: 'soundcloud', slug: 'soundcloud-downloader', name: 'SoundCloud', exampleUrl: 'https://soundcloud.com/artist/track-name' },
+  { id: 'twitch', slug: 'twitch-downloader', name: 'Twitch', exampleUrl: 'https://www.twitch.tv/videos/1234567890' },
+  { id: 'dailymotion', slug: 'dailymotion-downloader', name: 'Dailymotion', exampleUrl: 'https://www.dailymotion.com/video/x8abcde' },
+  { id: 'linkedin', slug: 'linkedin-downloader', name: 'LinkedIn', exampleUrl: 'https://www.linkedin.com/posts/username_activity-1234567890123456789' },
+  { id: 'tumblr', slug: 'tumblr-downloader', name: 'Tumblr', exampleUrl: 'https://username.tumblr.com/post/1234567890123' },
+  { id: 'vk', slug: 'vk-downloader', name: 'VK', exampleUrl: 'https://vk.com/video-12345678_123456789' },
+  { id: 'snapchat', slug: 'snapchat-downloader', name: 'Snapchat', exampleUrl: 'https://www.snapchat.com/spotlight/Xxxxxxxxxxxxxxxxxxxxxx' },
+]
+
+export function getDownloaderPlatformBySlug(slug: string): DownloaderPlatform | undefined {
+  return DOWNLOADER_PLATFORMS.find((platform) => platform.slug === slug)
+}