Fix port number in README.md to match app.py configuration

[Copilot]

README documented port 8000 but app.py runs on port 8080.

Changes

• Updated all port references in python/README.md from 8000 → 8080:
  • Server startup URL
  • Swagger UI URL
  • Health check example

# Before
curl http://localhost:8000/health

# After
curl http://localhost:8080/health

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