chore: finalize web UI root coverage and docs (#438)

## Summary

- verify that the embedded Web UI serves the SPA entrypoint directly at
the root path without a redirect
- use idiomatic Option handling in the embedded asset response path
- remove outdated setup sections from the English and Chinese project
READMEs

## Validation

- cargo test -p synctv-api-http --features web-ui
root_serves_spa_entrypoint_without_redirect
- make clippy-check
- cargo fmt --check
- git diff --check

README.md

@@ -45,71 +45,6 @@ Join the [SyncTV Telegram discussion](https://t.me/synctv) to talk with users an
 
 ![SyncTV contributors](https://contrib.nn.ci/api?repo=synctv-org/synctv&repo=synctv-org/synctv-app)
 
-## Quick Start
-
-Development environment from a full repository checkout:
-
-```bash
-# Starts PostgreSQL and Redis, then runs SyncTV locally with development settings.
-make dev-serve
-
-# Starts optional media/auth/storage dependencies too.
-make dev-stack
-
-# Runs real CLI/curl provider smoke tests through the Makefile dev startup path.
-make dev-smoke
-```
-
-Production Compose uses generated PostgreSQL, Redis, and application secrets:
-
-```bash
-# Requires Docker Compose and openssl.
-make compose-init
-
-# Edit SYNCTV_BOOTSTRAP_ROOT_PASSWORD in .env.synctv before starting.
-make compose-up
-```
-
-Validate configuration:
-
-```bash
-cargo +nightly run -p synctv --bin synctv -- config validate
-```
-
-Optional migration preflight. The server also runs embedded SQLx migrations automatically during startup:
-
-```bash
-cargo +nightly run -p synctv --bin synctv -- db migrate
-```
-
-Start locally:
-
-```bash
-cargo +nightly run -p synctv --bin synctv -- serve
-```
-
-### Embedded Web client
-
-The optional `web-ui` feature embeds a Flutter Web distribution in the HTTP
-server. The browser client always uses the page origin, so one deployed Web UI
-belongs to one SyncTV server. Build the configured Web distribution and server:
-
-```bash
-make web-ui-build
-make web-release-build
-```
-
-[`synctv-web-ui/README.md`](synctv-web-ui/README.md) documents prebuilt,
-local-project, and immutable Git sources together with cache and offline
-controls. The server provides SPA fallback, content types, ETags, Brotli/gzip
-variants, cache policy, and CSP. OAuth uses the normal SPA entry point, while
-provider verification uses its dedicated static page. API and media routes
-remain outside the application-shell cache.
-
-Keep the app and server protobuf snapshots aligned. Browser playback sends a
-versioned `PlaybackClientProfile`; Providers use it with the configured proxy
-policy to select direct or proxy routes before returning playback output.
-
 ## Documentation
 
 Read the complete documentation at [docs.syncs.tv](https://docs.syncs.tv).

README.zh-CN.md

@@ -44,49 +44,6 @@ SyncTV 是使用 Rust 实现的实时同步观影平台，支持媒体 Provider
 
 ![SyncTV 贡献者](https://contrib.nn.ci/api?repo=synctv-org/synctv&repo=synctv-org/synctv-app)
 
-## 快速开始
-
-开发环境需要完整源码仓库：
-
-```bash
-# 启动 PostgreSQL 和 Redis，然后用开发配置在本机运行 SyncTV。
-make dev-serve
-
-# 同时启动媒体、认证和对象存储等可选依赖。
-make dev-stack
-
-# 通过 Makefile dev 启动路径执行真实 CLI/curl provider smoke 测试。
-make dev-smoke
-```
-
-生产 Compose 使用自动生成的 PostgreSQL、Redis 和应用 secret：
-
-```bash
-# 需要 Docker Compose 和 openssl。
-make compose-init
-
-# 启动前编辑 .env.synctv 中的 SYNCTV_BOOTSTRAP_ROOT_PASSWORD。
-make compose-up
-```
-
-校验配置：
-
-```bash
-cargo +nightly run -p synctv --bin synctv -- config validate
-```
-
-可选 migration 预检。服务启动阶段也会自动执行 embedded SQLx migrations：
-
-```bash
-cargo +nightly run -p synctv --bin synctv -- db migrate
-```
-
-本地启动：
-
-```bash
-cargo +nightly run -p synctv --bin synctv -- serve
-```
-
 ## 文档
 
 完整文档见 [docs.syncs.tv](https://docs.syncs.tv)。

synctv-api-http/src/http/web_ui.rs

@@ -66,9 +66,9 @@ fn serve_path(path: &str, html_navigation: bool, headers: &HeaderMap) -> Respons
         )
             .into_response();
     }
-    find_asset(path)
-        .map(|asset| asset_response(asset, html_navigation, headers))
-        .unwrap_or_else(not_found)
+    find_asset(path).map_or_else(not_found, |asset| {
+        asset_response(asset, html_navigation, headers)
+    })
 }
 
 fn find_asset(path: &str) -> Option<&'static Asset> {
@@ -85,9 +85,8 @@ fn asset_response(asset: &'static Asset, html_navigation: bool, headers: &Header
     } else {
         "public, max-age=0, must-revalidate"
     };
-    let representation = match select_representation(asset, headers) {
-        Some(representation) => representation,
-        None => return StatusCode::NOT_ACCEPTABLE.into_response(),
+    let Some(representation) = select_representation(asset, headers) else {
+        return StatusCode::NOT_ACCEPTABLE.into_response();
     };
     if if_none_match_matches(headers, representation.etag) {
         let mut response = StatusCode::NOT_MODIFIED.into_response();
@@ -404,6 +403,27 @@ mod tests {
         assert!(!update_metadata_asset("main.dart.js"));
     }
 
+    #[tokio::test]
+    async fn root_serves_spa_entrypoint_without_redirect() {
+        assert!(
+            WEB_UI_AVAILABLE,
+            "the web-ui feature must embed a SPA entrypoint"
+        );
+
+        let response = index(HeaderMap::new()).await;
+
+        assert_eq!(response.status(), StatusCode::OK);
+        assert_eq!(
+            response.headers().get(header::CONTENT_TYPE),
+            Some(&HeaderValue::from_static("text/html; charset=utf-8"))
+        );
+        assert_eq!(
+            response.headers().get(header::CACHE_CONTROL),
+            Some(&HeaderValue::from_static("no-cache"))
+        );
+        assert!(response.headers().get(header::LOCATION).is_none());
+    }
+
     #[tokio::test]
     async fn oauth_callback_uses_the_spa_entrypoint() {
         let response = fallback(