[*] basic in-house cpp linting (#4039)

- add `#pragma once` to remainder files
- "correcter" defines (ANDROID), see https://groups.google.com/g/android-ndk/c/cf9_f1SLXls
- extra miscelly fixups

Signed-off-by: lizzie <lizzie@eden-emu.dev>

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4039
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>

src/frontend_common/config.cpp

@@ -1009,7 +1009,7 @@ std::string Config::AdjustOutputString(const std::string& string) {
 
     // Windows requires that two forward slashes are used at the start of a path for unmapped
     // network drives so we have to watch for that here
-#ifndef ANDROID
+#ifndef __ANDROID__
     if (string.substr(0, 2) == "//") {
         boost::replace_all(adjusted_string, "//", "/");
         adjusted_string.insert(0, "/");

src/frontend_common/data_manager.h

@@ -1,8 +1,7 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-#ifndef DATA_MANAGER_H
-#define DATA_MANAGER_H
+#pragma once
 
 #include "common/common_types.h"
 #include <string>
@@ -21,5 +20,3 @@ std::string ReadableBytesSize(u64 size) noexcept;
 u64 DataDirSize(DataDir dir);
 
 }; // namespace FrontendCommon::DataManager
-
-#endif // DATA_MANAGER_H

src/frontend_common/firmware_manager.cpp

@@ -13,7 +13,7 @@
 #include "core/crypto/key_manager.h"
 #include "frontend_common/content_manager.h"
 
-#ifdef ANDROID
+#ifdef __ANDROID__
 #include <jni.h>
 #include <common/android/id_cache.h>
 #include <common/android/android_common.h>
@@ -25,7 +25,7 @@ FirmwareManager::InstallKeys(std::string location, std::string extension) {
 
     const auto keys_dir = Common::FS::GetEdenPath(Common::FS::EdenPath::KeysDir);
 
-#ifdef ANDROID
+#ifdef __ANDROID__
     JNIEnv *env = Common::Android::GetEnvForThread();
 
     jstring jsrc = Common::Android::ToJString(env, location);

src/frontend_common/firmware_manager.h

@@ -1,8 +1,7 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-#ifndef FIRMWARE_MANAGER_H
-#define FIRMWARE_MANAGER_H
+#pragma once
 
 #include "common/common_types.h"
 #include "core/core.h"
@@ -107,5 +106,3 @@ inline std::pair<Service::Set::FirmwareVersionFormat, Result> GetFirmwareVersion
 
 // TODO(crueter): GET AS STRING
 }
-
-#endif

src/frontend_common/mod_manager.h

@@ -5,6 +5,7 @@
 
 #include <filesystem>
 #include <optional>
+#include <vector>
 #include "common/common_types.h"
 
 namespace FrontendCommon {