fix(adapters): upstream response decode fidelity (FWD-07, FWD-08, FWD-10, FWD-12) — core, tests follow

src/client/http_client.rs

@@ -175,14 +175,22 @@ pub enum HttpClientBuildError {
 }
 
 pub struct SharedHttpClient {
-    inner: ArcSwap<ClientWithMiddleware>,
-    config: ArcSwap<HttpClientConfig>,
+    inner: ArcSwap<SharedHttpInner>,
+}
+
+/// Joint holder for the client and its config so a reload swaps both in
+/// one atomic `ArcSwap::store` — a reader can never observe the new
+/// config paired with the previous client (FWD-12).
+#[derive(Clone)]
+struct SharedHttpInner {
+    client: Arc<ClientWithMiddleware>,
+    config: Arc<HttpClientConfig>,
 }
 
 impl std::fmt::Debug for SharedHttpClient {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("SharedHttpClient")
-            .field("config", &self.config.load())
+            .field("config", &self.inner.load().config)
             .finish_non_exhaustive()
     }
 }
@@ -196,27 +204,32 @@ impl SharedHttpClient {
     pub fn new(config: HttpClientConfig) -> Result<Self, HttpClientBuildError> {
         let client = build_client_sync(&config)?;
         Ok(Self {
-            inner: ArcSwap::from_pointee(client),
-            config: ArcSwap::from_pointee(config),
+            inner: ArcSwap::from_pointee(SharedHttpInner {
+                client: Arc::new(client),
+                config: Arc::new(config),
+            }),
         })
     }
 
     pub fn client(&self) -> Arc<ClientWithMiddleware> {
-        self.inner.load_full()
+        Arc::clone(&self.inner.load().client)
     }
 
     pub fn config(&self) -> Arc<HttpClientConfig> {
-        self.config.load_full()
+        Arc::clone(&self.inner.load().config)
     }
 
     /// Rebuild the underlying client and swap it in for new callers
     /// (in-flight requests complete on the previous client). PEM reads
     /// use `tokio::fs`, so this is safe to call from async contexts
-    /// without blocking a worker.
+    /// without blocking a worker. Client and config swap together in a
+    /// single atomic store (FWD-12).
     pub async fn reload(&self, config: HttpClientConfig) -> Result<(), HttpClientBuildError> {
         let client = build_client(&config).await?;
-        self.config.store(Arc::new(config));
-        self.inner.store(Arc::new(client));
+        self.inner.store(Arc::new(SharedHttpInner {
+            client: Arc::new(client),
+            config: Arc::new(config),
+        }));
         Ok(())
     }
 }