fix: use window inner_size() for resize on Wayland

Wayland surface always reports current_extent as 0xFFFFFFFF (undefined),
meaning the swapchain size is determined by the application, not the
surface. Previous code returned early when this happened, so resize
never worked — cells stretched to fill the window.

Fix: when current_extent is 0xFFFFFFFF, use winit's window.inner_size()
to get the actual pixel dimensions. This works on both X11 and Wayland.

Both renderers (ascii + graphics) updated.
109 tests, 0 failures

src/render/graphics.rs

@@ -65,7 +65,7 @@ pub struct GraphicsRenderer {
     instance_ptr: *mut ColorInstance,
     instance_count: usize,
 
-    _window: Arc<winit::window::Window>,
+    window: Arc<winit::window::Window>,
 }
 
 impl GraphicsRenderer {
@@ -300,7 +300,7 @@ impl GraphicsRenderer {
         image_available, render_finished, in_flight, frame_index: 0,
         vertex_buffer, vertex_memory, index_buffer, index_memory,
         instance_buffer, instance_memory, instance_ptr, instance_count,
-        _window: window,
+        window,
     })
 }
 
@@ -451,7 +451,12 @@ impl GraphicsRenderer {
         let new_extent = if caps.current_extent.width != u32::MAX {
             caps.current_extent
         } else {
-            return;
+            // Wayland: surface extent is undefined, use window inner size
+            let inner = self.window.inner_size();
+            vk::Extent2D {
+                width: inner.width.max(1),
+                height: inner.height.max(1),
+            }
         };
 
         if new_extent.width == self.swapchain_extent.width

src/render/vulkan.rs

@@ -85,6 +85,7 @@ pub struct VulkanRenderer {
     descriptor_set: vk::DescriptorSet,
     descriptor_set_layout: vk::DescriptorSetLayout,
     tick_count: u64,
+    window: Arc<winit::window::Window>,
 }
 
 impl VulkanRenderer {
@@ -157,6 +158,7 @@ impl VulkanRenderer {
             instance_buffer, instance_memory, instance_ptr, instance_count,
             descriptor_pool, descriptor_set, descriptor_set_layout,
             tick_count: 0,
+            window,
         })
     }
 
@@ -321,7 +323,12 @@ impl VulkanRenderer {
         let new_extent = if caps.current_extent.width != u32::MAX {
             caps.current_extent
         } else {
-            return;
+            // Wayland: surface extent is undefined, use window inner size
+            let inner = self.window.inner_size();
+            vk::Extent2D {
+                width: inner.width.max(1),
+                height: inner.height.max(1),
+            }
         };
 
         if new_extent.width == self.swapchain_extent.width