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/presentation/handler/downloader.rs

@@ -227,22 +227,6 @@ pub async fn download_videy(
     Ok(Json(DownloadResponse::ok(result)))
 }
 
-/// Handler for _tiktok_v2.
-pub async fn download_tiktok_v2(
-    Query(params): Query<DownloadParams>,
-) -> Result<Json<DownloadResponse>, AppError> {
-    let result = use_cases::download_tiktok_v2(&params.url).await?;
-    Ok(Json(DownloadResponse::ok(result)))
-}
-
-/// Handler for _twitter_v2.
-pub async fn download_twitter_v2(
-    Query(params): Query<DownloadParams>,
-) -> Result<Json<DownloadResponse>, AppError> {
-    let result = use_cases::download_twitter_v2(&params.url).await?;
-    Ok(Json(DownloadResponse::ok(result)))
-}
-
 /// Handler for _bilibili.
 pub async fn download_bilibili(
     Query(params): Query<DownloadParams>,

src/presentation/handler/misc.rs

@@ -0,0 +1,50 @@
+//! Axum handlers for misc utility endpoints.
+//!
+//! Ported from Shirokami-API `scraper/misc/*.js`.
+
+use axum::extract::Query;
+use axum::http::StatusCode;
+use axum::Json;
+use serde::Deserialize;
+use serde_json::Value;
+
+use crate::application::misc as use_cases;
+use crate::presentation::error::AppError;
+
+/// Query params for currency converter.
+#[derive(Deserialize)]
+pub struct CurrencyParams {
+    pub amount: Option<f64>,
+    pub from: Option<String>,
+    pub to: Option<String>,
+}
+
+/// GET /misc/currency-converter?amount=100&from=USD&to=IDR
+pub async fn currency_converter_handler(
+    Query(params): Query<CurrencyParams>,
+) -> Result<(StatusCode, Json<Value>), AppError> {
+    let amount = params.amount.unwrap_or(1.0);
+    let from = params.from.unwrap_or_else(|| "USD".to_string());
+    let to = params.to.unwrap_or_else(|| "IDR".to_string());
+
+    let result = use_cases::currency_converter(amount, &from, &to).await?;
+    Ok((StatusCode::OK, Json(result)))
+}
+
+/// GET /misc/harga-emas
+pub async fn harga_emas_handler() -> Result<(StatusCode, Json<Value>), AppError> {
+    let result = use_cases::harga_emas().await?;
+    Ok((StatusCode::OK, Json(result)))
+}
+
+/// GET /misc/kurs-bca
+pub async fn kurs_bca_handler() -> Result<(StatusCode, Json<Value>), AppError> {
+    let result = use_cases::kurs_bca().await?;
+    Ok((StatusCode::OK, Json(result)))
+}
+
+/// GET /misc/server-info
+pub async fn server_info_handler() -> Result<(StatusCode, Json<Value>), AppError> {
+    let result = use_cases::server_info().await?;
+    Ok((StatusCode::OK, Json(result)))
+}

src/presentation/handler/mod.rs

@@ -3,4 +3,5 @@ pub mod anime2;
 pub mod downloader;
 pub mod health;
 pub mod komik;
+pub mod misc;
 pub mod proxy;

src/presentation/router.rs

@@ -252,18 +252,27 @@ pub fn build_router(app_state: Arc<AppState>) -> anyhow::Result<Router> {
             "/download/videy",
             axum::routing::get(crate::presentation::handler::downloader::download_videy),
         )
-        .route(
-            "/download/tiktok/v2",
-            axum::routing::get(crate::presentation::handler::downloader::download_tiktok_v2),
-        )
-        .route(
-            "/download/twitter/v2",
-            axum::routing::get(crate::presentation::handler::downloader::download_twitter_v2),
-        )
         .route(
             "/download/bilibili",
             axum::routing::get(crate::presentation::handler::downloader::download_bilibili),
         )
+        // Misc routes
+        .route(
+            "/misc/currency-converter",
+            axum::routing::get(crate::presentation::handler::misc::currency_converter_handler),
+        )
+        .route(
+            "/misc/harga-emas",
+            axum::routing::get(crate::presentation::handler::misc::harga_emas_handler),
+        )
+        .route(
+            "/misc/kurs-bca",
+            axum::routing::get(crate::presentation::handler::misc::kurs_bca_handler),
+        )
+        .route(
+            "/misc/server-info",
+            axum::routing::get(crate::presentation::handler::misc::server_info_handler),
+        )
         // Health
         .route(
             "/health",