test: avoid public IP addresses in HTML-to-Markdown URL safety tests

[adulau]

Motivation

• Tests referenced real public addresses (93.184.216.34/35) which can make CI or local runs touch public IPs; using reserved test-net addresses avoids that risk.

Description

• Replaced occurrences of 93.184.216.34/93.184.216.35 with RFC 5737 TEST-NET-1 addresses (192.0.2.1 and 192.0.2.2) in tests/test_html_to_markdown.py.
• Renamed positive test cases to describe "unblocked" addresses instead of "public" addresses to clarify intent.
• Added a comment noting that 192.0.2.0/24 is reserved for documentation and examples.
• Kept redirect tests fully mocked using requests.Session so no real network requests occur during the tests.

Testing

• Ran python -m pytest tests/test_html_to_markdown.py and all tests passed (10 passed, 5 subtests passed).
• Ran git diff --check with no issues reported.

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Codex Task

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-25T14:46:27.430119Z	aed1171	PR opened
🔒 Security Review	✅ Completed 2026-09-25T14:46:53.531445Z	aed1171	PR opened

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