feat(qr-server): migrate to uv with PEP 723 inline dependencies

- Replace requirements.txt with inline script dependencies in server.py
- Add package.json with npm scripts for run-all.ts integration
- Update CI workflow to install uv via astral-sh/setup-uv@v5
- Update Docker commands to install uv for e2e tests
- Add Playwright golden screenshot for qr-server
- Update README with uv installation and usage instructions

tests/e2e/servers.spec.ts

@@ -49,6 +49,7 @@ const SERVERS = [
   { key: "customer-segmentation", name: "Customer Segmentation Server" },
   { key: "map-server", name: "CesiumJS Map Server" },
   { key: "pdf-server", name: "PDF Server" },
+  { key: "qr-server", name: "QR Server" },
   { key: "scenario-modeler", name: "SaaS Scenario Modeler" },
   { key: "shadertoy", name: "ShaderToy Server" },
   { key: "sheet-music", name: "Sheet Music Server" },