iOS lock step keyboard + metal

library/modules/ui/pipeline.sx

@@ -175,6 +175,11 @@ UIPipeline :: struct {
 
         self.renderer.begin(self.screen_width, self.screen_height, self.font.texture_id);
         self.renderer.process(@self.render_tree);
+        // Push any glyphs rasterized during process() to the GPU atlas BEFORE
+        // the final draw is recorded. On Metal we deferred per-render_text
+        // uploads so this is the single point where the atlas reaches the
+        // GPU. On the GL path it's a no-op (uploads already happened inline).
+        self.font.upload_atlas_to_gpu();
         self.renderer.flush();
 
         if !self.has_gpu {