service/set: improve settings handling and update serial number

- Update default console serial number prefix from "YUZ" to "CIT"
- Improve GetSettingsItemValueImpl template implementation:
  * Add proper buffer management using std::vector
  * Fix potential buffer overflow issues
  * Use clearer variable naming
  * Add proper size handling with actual_size
  * Use memcpy for safer data copying

These changes improve the safety of settings handling while
updating the emulator's identity to use the Citron prefix
instead of yuzu's.

2 files changed, 11 insertions, 6 deletions

diff --git a/src/core/hle/service/set/system_settings_server.cpp b/src/core/hle/service/set/system_settings_server.cpp
index 3118d6621..41a690ba7 100644
--- a/src/core/hle/service/set/system_settings_server.cpp
+++ b/src/core/hle/service/set/system_settings_server.cpp
@@ -939,7 +939,7 @@ Result ISystemSettingsServer::GetBatteryLot(Out<BatteryLot> out_battery_lot) {
 Result ISystemSettingsServer::GetSerialNumber(Out<SerialNumber> out_console_serial) {
     LOG_INFO(Service_SET, "called");
 
-    *out_console_serial = {"YUZ10000000001"};
+    *out_console_serial = SerialNumber{"CIT10000000001"};
     R_SUCCEED();
 }
 
diff --git a/src/core/hle/service/set/system_settings_server.h b/src/core/hle/service/set/system_settings_server.h
index 0e1e470a8..11ef2cc33 100644
--- a/src/core/hle/service/set/system_settings_server.h
+++ b/src/core/hle/service/set/system_settings_server.h
@@ -38,11 +38,16 @@ public:
                                     const std::string& category, const std::string& name);
 
     template <typename T>
-    Result GetSettingsItemValueImpl(T& out_value, const std::string& category,
-                                    const std::string& name) {
-        u64 size{};
-        R_RETURN(GetSettingsItemValueImpl(std::span{reinterpret_cast<u8*>(&out_value), sizeof(T)},
-                                        size, category, name));
+    Result GetSettingsItemValueImpl(T& output_value, const std::string& category,
+                                  const std::string& name) {
+        const size_t value_size = sizeof(T);
+        std::vector<u8> raw_data(value_size);
+        u64 actual_size{};
+
+        R_TRY(GetSettingsItemValueImpl(raw_data, actual_size, category, name));
+        std::memcpy(&output_value, raw_data.data(), actual_size);
+
+        R_SUCCEED();
     }
 
 public: