feat: add auth login options endpoint

server-rs/crates/api-server/src/login_options.rs

@@ -0,0 +1,33 @@
+use axum::{
+    Json,
+    extract::{Extension, State},
+};
+use serde::Serialize;
+
+use crate::{api_response::json_success_body, request_context::RequestContext, state::AppState};
+
+#[derive(Debug, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AuthLoginOptionsResponse {
+    pub available_login_methods: Vec<&'static str>,
+}
+
+pub async fn auth_login_options(
+    State(state): State<AppState>,
+    Extension(request_context): Extension<RequestContext>,
+) -> Json<serde_json::Value> {
+    let mut methods = Vec::new();
+    if state.config.sms_auth_enabled {
+        methods.push("phone");
+    }
+    if state.config.wechat_auth_enabled {
+        methods.push("wechat");
+    }
+
+    json_success_body(
+        Some(&request_context),
+        AuthLoginOptionsResponse {
+            available_login_methods: methods,
+        },
+    )
+}