fix(rendering): crash on window resize due to stale swapchain

- Mark swapchain dirty in Application's SDL resize handler (was only done
  in Window::pollEvents which is never called)
- Skip swapchain recreation when window is minimized (0×0 extent violates
  Vulkan spec and crashes vmaCreateImage)
- Guard aspect ratio division by zero when height is 0

Signed-off-by: Pavel Okhlopkov <pavel.okhlopkov@flant.com>

src/rendering/renderer.cpp

@@ -859,6 +859,8 @@ void Renderer::beginFrame() {
 
     // Handle swapchain recreation if needed
     if (vkCtx->isSwapchainDirty()) {
+        // Skip recreation while window is minimized (0×0 extent is a Vulkan spec violation)
+        if (window->getWidth() == 0 || window->getHeight() == 0) return;
         (void)vkCtx->recreateSwapchain(window->getWidth(), window->getHeight());
         // Rebuild water resources that reference swapchain extent/views
         if (waterRenderer) {