feat: add Dailymotion + Reddit downloader endpoints via yt-dlp

New platforms from Shirokami-style downloadter set:
- /download/dailymotion: real MP4/HLS streams (288p up to 2160p)
- /download/reddit: real v.redd.it HLS media for public posts
- detect + all-in-one dispatch updated

Both verified working from VPS with real URLs.

src/presentation/router.rs

@@ -236,6 +236,14 @@ pub fn build_router(app_state: Arc<AppState>) -> anyhow::Result<Router> {
             "/download/soundcloud",
             axum::routing::get(crate::presentation::handler::downloader::download_soundcloud),
         )
+        .route(
+            "/download/dailymotion",
+            axum::routing::get(crate::presentation::handler::downloader::download_dailymotion),
+        )
+        .route(
+            "/download/reddit",
+            axum::routing::get(crate::presentation::handler::downloader::download_reddit),
+        )
         .route(
             "/download/bilibili",
             axum::routing::get(crate::presentation::handler::downloader::download_bilibili),