docs: add utoipa OpenAPI annotations to all scraper endpoints

Add #[utoipa::path] + IntoParams to all new category handlers:
- downloader (25 routes): /download, /detect-platform, 23 platform handlers
- misc (4): currency-converter, harga-emas, kurs-bca, server-info
- stalk (8): github, youtube, ml, free-fire, genshin, twitter, tiktok, instagram
- weebs (5): anime-info, manga-info, whatanime, waifu (sfw/nsfw)
- search (5): bmkg, jadwal-sholat, weather, google, yt
- tool (6): whois, ip-location, tinyurl, check-hosting, hargapangan, cek-resi
- image (2): brat, brat-animated
- uploader (2): ryzencdn, serve-file
- ai (3): chat, gemini, image

Register all in ModuleApiDoc paths() with per-category tags.
Fix clippy warnings in touched handlers (expect/unwrap -> map_err, needless lifetimes).

/docs now documents the full scraper API surface (was only anime/komik).

src/presentation/handler/misc.rs

@@ -7,12 +7,13 @@ use axum::http::StatusCode;
 use axum::Json;
 use serde::Deserialize;
 use serde_json::Value;
+use utoipa::IntoParams;
 
 use crate::application::misc as use_cases;
 use crate::presentation::error::AppError;
 
 /// Query params for currency converter.
-#[derive(Deserialize)]
+#[derive(Deserialize, IntoParams)]
 pub struct CurrencyParams {
     pub amount: Option<f64>,
     pub from: Option<String>,
@@ -20,6 +21,17 @@ pub struct CurrencyParams {
 }
 
 /// GET /misc/currency-converter?amount=100&from=USD&to=IDR
+#[utoipa::path(
+    get,
+    path = "/misc/currency-converter",
+    tag = "misc",
+    operation_id = "currency_converter",
+    params(CurrencyParams),
+    responses(
+        (status = 200, description = "Currency conversion result", body = Value),
+        (status = 502, description = "Upstream error"),
+    )
+)]
 pub async fn currency_converter_handler(
     Query(params): Query<CurrencyParams>,
 ) -> Result<(StatusCode, Json<Value>), AppError> {
@@ -32,18 +44,48 @@ pub async fn currency_converter_handler(
 }
 
 /// GET /misc/harga-emas
+#[utoipa::path(
+    get,
+    path = "/misc/harga-emas",
+    tag = "misc",
+    operation_id = "harga_emas",
+    responses(
+        (status = 200, description = "Gold prices (Antam)", body = Value),
+        (status = 502, description = "Upstream error"),
+    )
+)]
 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
+#[utoipa::path(
+    get,
+    path = "/misc/kurs-bca",
+    tag = "misc",
+    operation_id = "kurs_bca",
+    responses(
+        (status = 200, description = "BCA exchange rates", body = Value),
+        (status = 502, description = "Upstream error"),
+    )
+)]
 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
+#[utoipa::path(
+    get,
+    path = "/misc/server-info",
+    tag = "misc",
+    operation_id = "server_info",
+    responses(
+        (status = 200, description = "Server info", body = Value),
+        (status = 502, description = "Upstream error"),
+    )
+)]
 pub async fn server_info_handler() -> Result<(StatusCode, Json<Value>), AppError> {
     let result = use_cases::server_info().await?;
     Ok((StatusCode::OK, Json(result)))