feat: add daily tasks and fix /admin139 admin entry

backend/tests/daily_task_service_test.cc

@@ -0,0 +1,34 @@
+#include <catch2/catch_test_macros.hpp>
+
+#include "csp/db/sqlite_db.h"
+#include "csp/services/auth_service.h"
+#include "csp/services/daily_task_service.h"
+#include "csp/services/user_service.h"
+
+TEST_CASE("daily task reward only once per day") {
+  auto db = csp::db::SqliteDb::OpenMemory();
+  csp::db::ApplyMigrations(db);
+
+  csp::services::AuthService auth(db);
+  const auto user = auth.Register("daily_task_user", "password123");
+
+  csp::services::UserService users(db);
+  csp::services::DailyTaskService daily(db);
+
+  const auto before = users.GetById(user.user_id);
+  REQUIRE(before.has_value());
+  // Register includes auto-login, which should complete login_checkin once.
+  REQUIRE(before->rating == 1);
+
+  REQUIRE(daily.CompleteTaskIfFirstToday(user.user_id,
+                                         csp::services::DailyTaskService::kTaskDailySubmit));
+  REQUIRE_FALSE(daily.CompleteTaskIfFirstToday(
+      user.user_id, csp::services::DailyTaskService::kTaskDailySubmit));
+
+  const auto after = users.GetById(user.user_id);
+  REQUIRE(after.has_value());
+  REQUIRE(after->rating == 2);
+
+  const auto tasks = daily.ListTodayTasks(user.user_id);
+  REQUIRE(tasks.size() == 4);
+}