test: verify Docker image builds and starts successfully with custom ports

[icebear0828]

This implements a CI smoke test in the existing GitHub Actions workflow (.github/workflows/ci-docker.yml) that verifies the Docker image can build and start successfully.

Changes:

• Replaced the single smoke job with a strategy.matrix to test ports 8080 and 8090.
• Added logic to generate a custom config_override/default.yaml to override the application's configuration when running on the custom port.
• Updated the docker run command to map the correct ports and mount the custom YAML configuration.
• Shortened the wait-for-healthcheck polling loop to wait up to 30 seconds (30 attempts at 1-second intervals).
• Updated the /health and /v1/models curl commands to dynamically fetch from ${{ matrix.port }}.
• Ensured proper resource cleanup at the end.

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PR created automatically by Jules for task 8266443933047342907 started by @icebear0828

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