fix(upload): make ConnectInfo optional to prevent 500 in release builds

upload_image declared ConnectInfo<SocketAddr> as a required Axum extractor,
but dioxus::server::serve() owns the listener and cannot call
into_make_service_with_connect_info::<SocketAddr>(), so the request extension
is absent on manually-merged routes. The extractor failed and Axum returned
500. dev (dx serve) passed by luck; release builds failed consistently.

Match serve_image's graceful-degradation pattern: take
Option<Extension<ConnectInfo<SocketAddr>>>, fall back to the 'unknown'
rate-limit bucket when missing. Production should deploy behind a reverse
proxy with TRUSTED_PROXY_COUNT so rate limiting keys on the real client IP.

Also correct the misleading comment in main.rs: axum 0.8 does have
ConnectInfoLayer/into_make_service_with_connect_info; the real blocker is
that Dioxus owns the listener.

src/api/upload.rs

@@ -7,7 +7,7 @@
 
 #[cfg(feature = "server")]
 use axum::{
-    extract::{ConnectInfo, Multipart},
+    extract::{ConnectInfo, Extension, Multipart},
     http::{HeaderMap, StatusCode},
     response::Json,
 };
@@ -70,13 +70,19 @@ fn validate_raw_image(data: &[u8], mime_type: &str) -> bool {
 ///
 /// 流程：限流 → 解析 session → 校验 admin → 读取 multipart → 校验类型/大小 →
 /// 转码（如适用）→ 按日期落盘 → 返回相对 URL。
+///
+/// `ConnectInfo` 以可选扩展注入：`dioxus::server::serve()` 接管了 listener，
+/// 无法调用 `into_make_service_with_connect_info::<SocketAddr>()`，所以这里
+/// 与 `serve_image` 保持一致的优雅降级——扩展缺失时退回 `"unknown"` 限流桶。
+/// 生产环境应在反向代理后部署并配置 `TRUSTED_PROXY_COUNT`，让限流拿到真实 IP。
 pub async fn upload_image(
-    ConnectInfo(addr): ConnectInfo<SocketAddr>,
+    connect_info: Option<Extension<ConnectInfo<SocketAddr>>>,
     headers: HeaderMap,
     mut multipart: Multipart,
 ) -> Result<Json<Value>, (StatusCode, Json<Value>)> {
     // 0. Rate limit check
-    let ip = crate::api::rate_limit::get_client_ip_with_peer(&headers, Some(addr));
+    let peer = connect_info.map(|Extension(ConnectInfo(addr))| addr);
+    let ip = crate::api::rate_limit::get_client_ip_with_peer(&headers, peer);
     if let Err(msg) = crate::api::rate_limit::check_upload_limit(&ip) {
         return Err((
             StatusCode::TOO_MANY_REQUESTS,

src/main.rs

@@ -326,10 +326,12 @@ fn main() {
             ));
 
             // 静态资源路由：图片文件服务。
-            // 注意：axum 0.8 没有 ConnectInfoLayer，且 dioxus::server::serve 不会把
-            // ConnectInfo 扩展传播到手动 merge 的路由，所以 serve_image 使用
-            // Option<Extension<ConnectInfo<SocketAddr>>> 优雅降级。生产环境应在反向代理后
-            // 部署并配置 TRUSTED_PROXY_COUNT，使限流能拿到真实客户端 IP。
+            // 注意：`dioxus::server::serve()` 接管了 listener 与 `into_make_service`
+            // 调用，没有机会换成 `into_make_service_with_connect_info::<SocketAddr>()`，
+            // 所以手动 merge 进来的路由（含 static_routes）拿不到 `ConnectInfo` 扩展。
+            // serve_image / upload_image 因此都用 `Option<Extension<ConnectInfo<SocketAddr>>>`
+            // 优雅降级。生产环境应在反向代理后部署并配置 TRUSTED_PROXY_COUNT，
+            // 使限流能拿到真实客户端 IP。
             let static_routes = axum::Router::new()
                 .route(
                     "/uploads/{*path}",