feat: add Streamable downloader endpoint + fix detect false-positive

- /download/streamable: real MP4 via yt-dlp (verified ftypisom)
- Fix detect_platform: t.co substring greedily matched reddit.com
  ('.reddit.com' contains 't.co') - now requires t.co/ path
- Removed duplicate reddit branch in detect chain

src/application/downloader.rs

@@ -115,6 +115,10 @@ pub async fn download_reddit(url: &str) -> Result<DownloadResult, ScrapingError>
     DownloaderRepository::download_reddit(url).await
 }
 
+pub async fn download_streamable(url: &str) -> Result<DownloadResult, ScrapingError> {
+    DownloaderRepository::download_streamable(url).await
+}
+
 pub async fn download_bilibili(url: &str) -> Result<DownloadResult, ScrapingError> {
     DownloaderRepository::download_bilibili(url).await
 }
@@ -131,10 +135,12 @@ pub fn detect_platform(url: &str) -> String {
         "youtube".to_string()
     } else if url.contains("open.spotify.com") || url.contains("spotify.link") {
         "spotify".to_string()
-    } else if url.contains("twitter.com") || url.contains("x.com") || url.contains("t.co") {
+    } else if url.contains("twitter.com") || url.contains("x.com") || url.contains("t.co/") {
         "twitter".to_string()
     } else if url.contains("pinterest") {
         "pinterest".to_string()
+    } else if url.contains("reddit.com") || url.contains("redd.it") {
+        "reddit".to_string()
     } else if url.contains("mega.nz") || url.contains("mega.io") {
         "mega".to_string()
     } else if url.contains("terabox") || url.contains("nfile") {
@@ -157,8 +163,8 @@ pub fn detect_platform(url: &str) -> String {
         "soundcloud".to_string()
     } else if url.contains("dailymotion.com") {
         "dailymotion".to_string()
-    } else if url.contains("reddit.com") || url.contains("redd.it") {
+    } else if url.contains("streamable.com") {
-        "reddit".to_string()
+        "streamable".to_string()
     } else if url.contains("bilibili.com") || url.contains("b23.tv") {
         "bilibili".to_string()
     } else {

src/infrastructure/repository/downloader.rs

@@ -470,6 +470,7 @@ impl DownloaderRepository {
             "soundcloud" => Self::download_soundcloud(url).await,
             "dailymotion" => Self::download_dailymotion(url).await,
             "reddit" => Self::download_reddit(url).await,
+            "streamable" => Self::download_streamable(url).await,
             "bilibili" => Self::download_bilibili(url).await,
             _ => fetch_all_in_one(url).await,
         }
@@ -602,6 +603,11 @@ impl DownloaderRepository {
         fetch_reddit(url).await
     }
 
+    /// Streamable video via yt-dlp.
+    pub async fn download_streamable(url: &str) -> Result<DownloadResult, ScrapingError> {
+        fetch_streamable(url).await
+    }
+
     /// Bilibili video via b23.tv short link expansion.
     pub async fn download_bilibili(url: &str) -> Result<DownloadResult, ScrapingError> {
         fetch_bilibili(url).await
@@ -2401,6 +2407,102 @@ pub async fn fetch_reddit(url: &str) -> Result<DownloadResult, ScrapingError> {
     Ok(result)
 }
 
+// ============================================================================
+// Streamable downloader (via yt-dlp)
+// ============================================================================
+
+pub async fn fetch_streamable(url: &str) -> Result<DownloadResult, ScrapingError> {
+    if !url.contains("streamable.com") {
+        return Err(ScrapingError::Http("Invalid Streamable URL".to_string()));
+    }
+
+    let data = run_ytdlp_json(url, &["-f", "best"]).await?;
+
+    let title = data
+        .get("title")
+        .and_then(|v| v.as_str())
+        .map(|s| s.to_string());
+    let thumbnail = data
+        .get("thumbnail")
+        .and_then(|v| v.as_str())
+        .map(|s| s.to_string());
+
+    let mut result = DownloadResult::success(title);
+    result.thumbnail = thumbnail;
+    result.provider = Some("yt-dlp".to_string());
+
+    let mut seen = std::collections::HashSet::new();
+    if let Some(fmts) = data.get("formats").and_then(|v| v.as_array()) {
+        for f in fmts {
+            if let (Some(furl), Some(ext_val)) = (
+                f.get("url").and_then(|v| v.as_str()),
+                f.get("ext").and_then(|v| v.as_str()),
+            ) {
+                if ext_val == "mhtml" {
+                    continue;
+                }
+                let url_string = furl.to_string();
+                if seen.insert(url_string.clone()) {
+                    result.media.push(MediaItem {
+                        url: url_string,
+                        quality: f
+                            .get("height")
+                            .and_then(|v| v.as_u64())
+                            .map(|h| format!("{}p", h)),
+                        file_type: Some(MediaType::Video),
+                        extension: Some(ext_val.to_string()),
+                        thumbnail: data
+                            .get("thumbnail")
+                            .and_then(|v| v.as_str())
+                            .map(|s| s.to_string()),
+                        file_size: f
+                            .get("filesize")
+                            .and_then(|v| v.as_u64())
+                            .map(format_filesize),
+                        size_bytes: f.get("filesize").and_then(|v| v.as_u64()),
+                        frame_width: f
+                            .get("width")
+                            .and_then(|v| v.as_u64())
+                            .map(|w| w.to_string()),
+                        frame_height: f
+                            .get("height")
+                            .and_then(|v| v.as_u64())
+                            .map(|h| h.to_string()),
+                        note: None,
+                    });
+                }
+            }
+        }
+    }
+
+    if result.media.is_empty() {
+        if let Some(dl_url) = data.get("url").and_then(|v| v.as_str()) {
+            result.media.push(MediaItem {
+                url: dl_url.to_string(),
+                quality: None,
+                file_type: Some(MediaType::Video),
+                extension: Some(
+                    data.get("ext")
+                        .and_then(|v| v.as_str())
+                        .unwrap_or("mp4")
+                        .to_string(),
+                ),
+                thumbnail: data
+                    .get("thumbnail")
+                    .and_then(|v| v.as_str())
+                    .map(|s| s.to_string()),
+                file_size: None,
+                size_bytes: None,
+                frame_width: None,
+                frame_height: None,
+                note: None,
+            });
+        }
+    }
+
+    Ok(result)
+}
+
 // ============================================================================
 // Pinterest downloader
 // ============================================================================

src/presentation/handler/downloader.rs

@@ -211,6 +211,14 @@ pub async fn download_reddit(
     Ok(Json(DownloadResponse::ok(result)))
 }
 
+/// Handler for _streamable.
+pub async fn download_streamable(
+    Query(params): Query<DownloadParams>,
+) -> Result<Json<DownloadResponse>, AppError> {
+    let result = use_cases::download_streamable(&params.url).await?;
+    Ok(Json(DownloadResponse::ok(result)))
+}
+
 /// Handler for _bilibili.
 pub async fn download_bilibili(
     Query(params): Query<DownloadParams>,

src/presentation/router.rs

@@ -244,6 +244,10 @@ pub fn build_router(app_state: Arc<AppState>) -> anyhow::Result<Router> {
             "/download/reddit",
             axum::routing::get(crate::presentation::handler::downloader::download_reddit),
         )
+        .route(
+            "/download/streamable",
+            axum::routing::get(crate::presentation::handler::downloader::download_streamable),
+        )
         .route(
             "/download/bilibili",
             axum::routing::get(crate::presentation::handler::downloader::download_bilibili),