chore(env): add bundled test accounts and seed admin

backend/src/main.cc

@@ -1,7 +1,9 @@
 #include <drogon/drogon.h>
 
 #include "csp/app_state.h"
+#include "csp/services/auth_service.h"
 
+#include <cstdlib>
 #include <filesystem>
 
 int main(int argc, char** argv) {
@@ -11,6 +13,22 @@ int main(int argc, char** argv) {
 
   csp::AppState::Instance().Init(db_path);
 
+  // Optional seed admin user for dev/test.
+  {
+    const char* u = std::getenv("CSP_SEED_ADMIN_USERNAME");
+    const char* p = std::getenv("CSP_SEED_ADMIN_PASSWORD");
+    if (u && p && std::string(u).size() > 0 && std::string(p).size() > 0) {
+      try {
+        csp::services::AuthService auth(csp::AppState::Instance().db());
+        auth.Register(u, p);
+        LOG_INFO << "seed admin user created: " << u;
+      } catch (const std::exception& e) {
+        // Most likely UNIQUE constraint (already exists)
+        LOG_INFO << "seed admin user skipped: " << e.what();
+      }
+    }
+  }
+
   // CORS (dev-friendly). In production, prefer reverse proxy same-origin.
   drogon::app().registerPreRoutingAdvice([](const drogon::HttpRequestPtr& req,
                                            drogon::AdviceCallback&& cb,