Build fails on GCC 16: 'close'/'read' not declared in this scope (missing #include <unistd.h>)

Summary

Building from main fails to compile with GCC 16 because several source files
call POSIX functions (close, read, open) without including <unistd.h>.
They currently compile only because older libstdc++/glibc headers pulled
<unistd.h> in transitively. GCC 16 / the matching libstdc++ no longer does, so
the calls are now unresolved and the build breaks.

This is purely a missing-include issue — the fix is one #include <unistd.h>
per affected translation unit.

Environment

• OS: Fedora Linux 44
• Compiler: gcc-c++ 16.1.1 (Red Hat 16.1.1-2)
• CMake: 4.3.0
• Qt: 6.11.1
• KDE Plasma / KWin: 6.6.5 (Wayland)
• Build: KWin plugin — cmake -S . -B build -DINPUTACTIONS_BUILD_KWIN=ON -DCMAKE_BUILD_TYPE=Release
• Superproject commit: c5b721f (submodules: core @ 0d72dbd, libevdev-cpp @ 4707a9e)

Errors

.../libevdev-cpp/src/libevdev-cpp/Device.cpp:50:9: error: 'close' was not declared in this scope; did you mean 'pclose'?
   50 |         close(fd);
.../libevdev-cpp/src/libevdev-cpp/Device.cpp:67:9: error: 'close' was not declared in this scope; did you mean 'pclose'?

.../core/src/libinputactions/interfaces/implementations/FileConfigProvider.cpp:61:9: error: 'close' was not declared in this scope; did you mean 'pclose'?
   61 |         close(m_inotifyFd);
.../core/src/libinputactions/interfaces/implementations/FileConfigProvider.cpp:83:12: error: 'read' was not declared in this scope; did you mean 'fread'?
   83 |     while (read(m_inotifyFd, &buffer, sizeof(buffer)) > 0) {

(open() happens to resolve because <fcntl.h> is already included; only the
<unistd.h> symbols are affected.)

Affected files & fix

Add #include <unistd.h> to each:

Needed for the KWin plugin build:

• InputActions/libevdev-cpp → src/libevdev-cpp/Device.cpp (close, open)
• InputActions/core → src/libinputactions/interfaces/implementations/FileConfigProvider.cpp (close, read)

Also needed for the standalone build:

• InputActions/libinput-cpp → src/libinput-cpp/PathContext.cpp
• InputActions/standalone → src/daemon/input/StandaloneInputBackend.cpp
• InputActions/standalone → src/ipc/libinputactions-standalone-ipc/MessageSocketConnection.cpp
• InputActions/standalone → src/ipc/libinputactions-standalone-ipc/MessageSocketConnection.h

Patch

# InputActions/libevdev-cpp — src/libevdev-cpp/Device.cpp
 #include "logging.h"
 #include <QLoggingCategory>
 #include <fcntl.h>
+#include <unistd.h>
 #include <libevdev/libevdev.h>

# InputActions/core — src/libinputactions/interfaces/implementations/FileConfigProvider.cpp
 #include "FileConfigProvider.h"
+#include <unistd.h>
 #include <QDir>
 #include <QFile>

# InputActions/libinput-cpp — src/libinput-cpp/PathContext.cpp
 #include "PathContext.h"
+#include <unistd.h>
 #include "Device.h"
 #include "Event.h"
 #include <fcntl.h>

# InputActions/standalone — src/daemon/input/StandaloneInputBackend.cpp
 #include "StandaloneInputBackend.h"
+#include <unistd.h>
 #include "StandaloneInputDevice.h"

# InputActions/standalone — src/ipc/libinputactions-standalone-ipc/MessageSocketConnection.cpp
 #include "MessageSocketConnection.h"
+#include <unistd.h>

# InputActions/standalone — src/ipc/libinputactions-standalone-ipc/MessageSocketConnection.h
 #include "JsonSerializer.h"
+#include <unistd.h>
 #include "messages.h"

With these includes added, the KWin plugin builds and links cleanly (verified on
the environment above).