[*] 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/qt_common/util/fs.h

@@ -1,12 +1,12 @@
 // SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
+#pragma once
+
 #include <filesystem>
 #include <optional>
 #include "common/common_types.h"
 
-#pragma once
-
 namespace QtCommon::FS {
 
 void LinkRyujinx(std::filesystem::path& from, std::filesystem::path& to);