feat: redesign landing page with PCB schematic aesthetic and update Docker Hub description

- Remove gradient text, floating chips and heart icon from landing page
- Add circuit schematic SVG hero (Arduino + R1 + LED + oscilloscope window)
- Add peter-evans/dockerhub-description step to CI workflow

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/docker-publish.yml

@@ -55,3 +55,12 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
+
+      - name: Update Docker Hub description
+        uses: peter-evans/dockerhub-description@v4
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+          repository: ${{ secrets.DOCKERHUB_USERNAME }}/velxio
+          short-description: "Local, open-source Arduino emulator — real AVR8 emulation, 48+ components, Monaco editor, arduino-cli backend."
+          readme-filepath: ./README.md