Publish platform-specific Flutter captures

.github/workflows/runtime.yml

@@ -25,8 +25,8 @@ jobs:
       - name: Analyze
         run: flutter analyze lib test
 
-      - name: Test responsive runtime captures
-        run: flutter test
+      - name: Test and generate Linux runtime captures
+        run: flutter test --update-goldens
 
       - name: Verify lifecycle
         shell: pwsh
@@ -35,6 +35,6 @@ jobs:
       - name: Upload golden captures
         uses: actions/upload-artifact@v7
         with:
-          name: eveflutter-captures-${{ github.sha }}
+          name: eveflutter-linux-captures-${{ github.sha }}
           path: test/goldens/*.png
           if-no-files-found: error