chore: bump NGINX to 1.30.0

[iYism]

Motivation

• Ensure the image build and documentation reference the newer NGINX 1.30.0 release.

Description

• Updated NGINX_VERSION in Dockerfile from 1.29.7 to 1.30.0 and synchronized the NGINX version in README.md to 1.30.0.

Testing

• Ran git status --short && git diff -- Dockerfile README.md and rg -n "NGINX_VERSION" Dockerfile to verify the edits, both succeeded.
• Committed the changes with git add Dockerfile README.md && git commit -m "chore: upgrade nginx to 1.30.0", which succeeded.
• No image build or CI/test suite was executed for this version/documentation-only change.

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Codex Task