Revalidating cache on app assets; site title survives SPA navigation

pkg files keep stable names across releases, so an uncontrolled
browser cache could pair last release's wasm with the new server's
server-fn wire format - every page then renders its error branch
(redoal.com's 'Nothing here' after v0.2.0). Cache-Control: no-cache
on /pkg and /yes.js makes clients revalidate (a 304 per load) instead
of guessing. The content-declared site title also moves out of the
question Suspense: remounting with each navigation lost the
leptos_meta race to the compile-time fallback, flipping redoal.com's
tab to 'uhhm' on the first client-side nav.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Cargo.toml

@@ -19,7 +19,7 @@ axum = { version = "0.8", features = ["multipart"], optional = true }
 aws-sdk-s3 = { version = "1", optional = true }
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "signal"], optional = true }
 tower = { version = "0.5", optional = true }
-tower-http = { version = "0.6", features = ["fs"], optional = true }
+tower-http = { version = "0.6", features = ["fs", "set-header"], optional = true }
 tower-sessions = { version = "0.14", optional = true }
 async-nats = { version = "0.38", optional = true }
 arc-swap = { version = "1", optional = true }

src/app.rs

@@ -89,6 +89,18 @@ fn QuestionPage() -> impl IntoView {
     let site = Resource::new(|| (), |_| get_site());
 
     view! {
+        // The content-declared site title lives OUTSIDE the question
+        // Suspense: tied to the per-page resource it unmounted on every
+        // SPA navigation and lost the leptos_meta race to App's
+        // compile-time SITE_NAME fallback (redoal.com flashing to
+        // "uhhm" on nav - and staying there). Out here it mounts once
+        // and covers every branch, NotFound included.
+        {move || {
+            site.get()
+                .and_then(|r| r.ok())
+                .and_then(|s| s.title)
+                .map(|t| view! { <Title text=t/> })
+        }}
         <Suspense fallback=|| {
             view! {
                 <main class="loading">
@@ -109,13 +121,6 @@ fn QuestionPage() -> impl IntoView {
                         Ok(Some(page)) => {
                             let current = user_res.and_then(|r| r.ok()).flatten();
                             view! {
-                                // A second <Title> outranks App's
-                                // SITE_NAME fallback only when content
-                                // actually declares one.
-                                {site_cfg
-                                    .title
-                                    .clone()
-                                    .map(|t| view! { <Title text=t/> })}
                                 <QuestionView
                                     question=page.question
                                     chain_gate=page.chain_gate

src/main.rs

@@ -143,7 +143,22 @@ async fn main() -> anyhow::Result<()> {
         .route("/upload", post(upload::upload))
         .route("/gitea-repo", get(content::gitea_repo_handler))
         .route("/automation/kv/{bucket}", get(content::automation_kv_handler))
-        .nest_service("/pkg", ServeDir::new(pkg_dir))
+        // no-cache = "revalidate before reuse", not "don't cache":
+        // pkg files keep the same names across releases (portal.js,
+        // portal.wasm), and without this browsers heuristically cache
+        // them - a stale wasm from the previous release then talks to
+        // a server whose server-fn wire format has moved on and every
+        // page renders as its error branch. A 304 per load is the
+        // price of never shipping that skew again.
+        .nest_service(
+            "/pkg",
+            tower::ServiceBuilder::new()
+                .layer(tower_http::set_header::SetResponseHeaderLayer::overriding(
+                    axum::http::header::CACHE_CONTROL,
+                    axum::http::HeaderValue::from_static("no-cache"),
+                ))
+                .service(ServeDir::new(pkg_dir)),
+        )
         .nest_service("/fonts", ServeDir::new(fonts_dir))
         .route_service("/favicon-light.svg", ServeFile::new(favicon_light_path))
         .route_service("/favicon-dark.svg", ServeFile::new(favicon_dark_path))
@@ -152,7 +167,17 @@ async fn main() -> anyhow::Result<()> {
             "/swiper-element-bundle.min.js",
             ServeFile::new(swiper_path),
         )
-        .route_service("/yes.js", ServeFile::new(yes_path))
+        // Same skew concern as /pkg: the wasm's raw_module import and
+        // the hero's inline script both load this by fixed name.
+        .route_service(
+            "/yes.js",
+            tower::ServiceBuilder::new()
+                .layer(tower_http::set_header::SetResponseHeaderLayer::overriding(
+                    axum::http::header::CACHE_CONTROL,
+                    axum::http::HeaderValue::from_static("no-cache"),
+                ))
+                .service(ServeFile::new(yes_path)),
+        )
         .leptos_routes_with_context(
             &state,
             routes,