qt: gate EglDmabufTarget references on the Vulkan variant

Pass 1 made src/opengl/EglDmabufTarget.cpp opengl-variant-only in
qt/CMakeLists.txt, but GhosttySurface kept referencing
opengl::EglDmabufTarget unconditionally — the Vulkan link failed
with undefined references to ::create and ::~EglDmabufTarget.

Wrap the field declaration, the include, and every call site that
touches m_eglTarget with #ifndef GHASTTY_USE_VULKAN. The runtime
m_useVulkan branches above each block already make these paths
dead on Vulkan builds; preprocessing them out additionally drops
the link reference, which matches the libEGL gating in the cmake
file (Vulkan binary stays free of libEGL).

Co-Authored-By: claude-flow <ruv@ruv.net>

qt/src/GhosttySurface.cpp

@@ -10,8 +10,9 @@
 #include "Util.h"
 #ifdef GHASTTY_USE_VULKAN
 #include "vulkan/Host.h"
-#endif
+#else
 #include "opengl/EglDmabufTarget.h"
+#endif
 #include "wayland/DmabufRegistry.h"
 #include "wayland/SubsurfacePresenter.h"
 
@@ -324,6 +325,11 @@ void GhosttySurface::syncSurfaceSize() {
     return;
   }
 
+#ifndef GHASTTY_USE_VULKAN
+  // OpenGL path. Vulkan-variant builds always take the `m_useVulkan`
+  // branch above and never reach here; the entire block is excluded
+  // at preprocessor time so the Vulkan binary doesn't pull in
+  // EglDmabufTarget (and transitively libEGL).
   if (!makeCurrent()) return;
   m_eglTarget.reset();
   delete m_fbo;
@@ -362,6 +368,7 @@ void GhosttySurface::syncSurfaceSize() {
   ghostty_surface_set_size(m_surface, static_cast<uint32_t>(w),
                            static_cast<uint32_t>(h));
   renderTerminal();
+#endif
 }
 
 void GhosttySurface::moveEvent(QMoveEvent *) {
@@ -432,11 +439,14 @@ bool GhosttySurface::event(QEvent *e) {
       // re-creates the QPA window (QSplitter reparent, fullscreen
       // toggle, screen change). Make the owning context current
       // before tearing down. Vulkan-variant builds have no
-      // `m_context` and skip the makeCurrent.
+      // `m_context` or `m_eglTarget` and the whole block is
+      // preprocessed out below.
+#ifndef GHASTTY_USE_VULKAN
       if (m_eglTarget) {
         if (m_context) makeCurrent();
         m_eglTarget.reset();
       }
+#endif
       m_subsurfacePresenter.reset();
     }
     // SurfaceCreated is handled implicitly: the next QEvent::Show
@@ -593,6 +603,10 @@ void GhosttySurface::renderTerminal() {
     return;
   }
 
+#ifndef GHASTTY_USE_VULKAN
+  // OpenGL path. Vulkan-variant builds always take the early
+  // `m_useVulkan` return above; preprocessing the block out keeps
+  // the Vulkan binary free of EglDmabufTarget (and libEGL).
   if (!makeCurrent()) return;
   if (!m_eglTarget && !m_fbo) return;
 
@@ -658,6 +672,7 @@ void GhosttySurface::renderTerminal() {
   m_fbo->release();
 
   update();
+#endif
 }
 
 void GhosttySurface::paintEvent(QPaintEvent *) {

qt/src/GhosttySurface.h

@@ -18,9 +18,11 @@
 namespace wayland {
 class SubsurfacePresenter;
 }
+#ifndef GHASTTY_USE_VULKAN
 namespace opengl {
 class EglDmabufTarget;
 }
+#endif
 
 class MainWindow;
 class QContextMenuEvent;
@@ -286,6 +288,7 @@ private:
   QOpenGLContext *m_context = nullptr;
   QOffscreenSurface *m_offscreen = nullptr;
   QOpenGLFramebufferObject *m_fbo = nullptr;
+#ifndef GHASTTY_USE_VULKAN
   // Dmabuf-exporting GL target (zero-copy path). Set when the EGL
   // display advertises EGL_MESA_image_dma_buf_export and the
   // wl_subsurface presenter is up; the renderer draws into this
@@ -293,7 +296,14 @@ private:
   // subsurface — no glReadPixels, no QImage, no QPainter blit.
   // Stays null when EGL support is missing or the subsurface failed
   // to bring up, and the legacy m_fbo path runs as fallback.
+  //
+  // Vulkan-variant builds export dmabufs directly from
+  // VkDeviceMemory via VK_KHR_external_memory_fd and never touch
+  // EGL, so the field (and the entire EglDmabufTarget translation
+  // unit) is excluded from those binaries — matching the libEGL
+  // gating in qt/CMakeLists.txt.
   std::unique_ptr<opengl::EglDmabufTarget> m_eglTarget;
+#endif
   QImage m_image;                      // last frame, read back from m_fbo
 
   // True when this surface is using the Vulkan platform. The