feat(misc): add misc endpoints (currency-converter, harga-emas, kurs-bca, server-info)

Ported from Shirokami-API scraper/misc/*.js:
- /misc/currency-converter (wise.com scrape, amount/from/to)
- /misc/harga-emas (harga-emas.org Antam table)
- /misc/kurs-bca (bca.co.id jual/beli)
- /misc/server-info (OS/CPU/RAM/disk from /proc)

Also: remove /download/tiktok/v2 + /download/twitter/v2 as separate routes;
douyin.wtf + twitsave now internal fallback steps in the primary
fetch_tiktok/fetch_twitter chains (v2 = fallback per user directive).

src/application/downloader.rs

@@ -123,14 +123,6 @@ pub async fn download_videy(url: &str) -> Result<DownloadResult, ScrapingError>
     DownloaderRepository::download_videy(url).await
 }
 
-pub async fn download_tiktok_v2(url: &str) -> Result<DownloadResult, ScrapingError> {
-    DownloaderRepository::download_tiktok_v2(url, None).await
-}
-
-pub async fn download_twitter_v2(url: &str) -> Result<DownloadResult, ScrapingError> {
-    DownloaderRepository::download_twitter_v2(url, None).await
-}
-
 pub async fn download_bilibili(url: &str) -> Result<DownloadResult, ScrapingError> {
     DownloaderRepository::download_bilibili(url).await
 }

src/application/misc.rs

@@ -0,0 +1,33 @@
+//! Application use-cases for misc utilities.
+
+use crate::domain::error::ScrapingError;
+use crate::infrastructure::repository::misc as Repo;
+use serde_json::Value;
+
+/// Currency converter.
+pub async fn currency_converter(amount: f64, from: &str, to: &str) -> Result<Value, ScrapingError> {
+    Repo::fetch_currency_converter(amount, from, to)
+        .await
+        .map_err(ScrapingError::Http)
+}
+
+/// Harga emas Antam.
+pub async fn harga_emas() -> Result<Value, ScrapingError> {
+    Repo::fetch_harga_emas()
+        .await
+        .map_err(ScrapingError::Http)
+}
+
+/// Kurs BCA (jual/beli).
+pub async fn kurs_bca() -> Result<Value, ScrapingError> {
+    Repo::fetch_kurs_bca()
+        .await
+        .map_err(ScrapingError::Http)
+}
+
+/// Server info (OS/CPU/RAM/disk).
+pub async fn server_info() -> Result<Value, ScrapingError> {
+    Repo::fetch_server_info()
+        .await
+        .map_err(ScrapingError::Http)
+}

src/application/mod.rs

@@ -2,4 +2,5 @@ pub mod anime;
 pub mod anime2;
 pub mod downloader;
 pub mod komik;
+pub mod misc;
 pub mod proxy;