minor: yugioh support added

core/src/infra/CprHttpClient.cpp

@@ -3,19 +3,40 @@
 #include <cpr/cpr.h>
 
 #include <string>
+#include <utility>
 
 namespace ccm {
 
-CprHttpClient::CprHttpClient(std::chrono::milliseconds timeout) : timeout_(timeout) {}
+CprHttpClient::CprHttpClient(std::chrono::milliseconds timeout)
+    : timeout_(timeout),
+      session_(std::make_unique<cpr::Session>()) {
+    // Configure session-wide options once; every Get() then only updates
+    // the URL. libcurl's connection cache lives inside the easy handle, so
+    // reusing one Session across calls is what gets us TLS keep-alive.
+    session_->SetTimeout(cpr::Timeout{timeout_});
+    // `Accept: application/json` breaks some CDNs that refuse non-JSON bodies
+    // (preview pipeline also GETs raw JPG/PNG). Wildcard keeps JSON APIs happy.
+    session_->SetHeader(cpr::Header{
+        {"User-Agent", "card-collection-manager-3/0.1"},
+        {"Accept",     "*/*"},
+    });
+    session_->SetRedirect(cpr::Redirect{/*max_redirects=*/10L,
+                                        /*follow=*/true,
+                                        /*cont_send_cred=*/false,
+                                        cpr::PostRedirectFlags::POST_ALL});
+}
+
+CprHttpClient::~CprHttpClient() = default;
 
 Result<std::string> CprHttpClient::get(std::string_view url) {
-    cpr::Response r = cpr::Get(
-        cpr::Url{std::string(url)},
-        cpr::Timeout{timeout_},
-        // Identify ourselves; some APIs rate-limit unknown agents harshly.
-        cpr::Header{{"User-Agent", "card-collection-manager-3/0.1"},
-                    {"Accept",     "application/json"}}
-    );
+    // libcurl easy handles (and therefore cpr::Session) are not thread-safe.
+    // We serialize callers here; the preview path is single-flight already
+    // (one fetch per BaseSelectedCardPanel selection change), so contention
+    // is negligible.
+    std::lock_guard<std::mutex> lock(sessionMutex_);
+
+    session_->SetUrl(cpr::Url{std::string(url)});
+    cpr::Response r = session_->Get();
 
     if (r.error) {
         return Result<std::string>::err("HTTP error: " + r.error.message);