fix(agent): detect modern services.ai.azure.com in _is_azure_openai_url()

[liuhao1024]

What does this PR do?

Extends _is_azure_openai_url() to detect modern Azure OpenAI endpoints (*.services.ai.azure.com) in addition to the legacy *.openai.azure.com pattern. This ensures Azure-specific routing works correctly for post-2024 Azure OpenAI resources.

Related Issue

Fixes #47666

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)

Changes Made

• run_agent.py: Extended _is_azure_openai_url() substring check to also match ai.azure.com, covering modern *.services.ai.azure.com endpoints. Updated docstring to document both URL patterns.
• tests/run_agent/test_run_agent.py: Added assertions for *.services.ai.azure.com URLs in test_is_azure_openai_url_detection.

How to Test

1. Run pytest tests/run_agent/test_run_agent.py::TestGpt5ApiModeRouting -xvs — all 4 tests should pass
2. Verify the new assertions: services.ai.azure.com URLs return True, legacy openai.azure.com still works, and non-Azure URLs still return False

Checklist

Code

• I've read the Contributing Guide
• My commit messages follow Conventional Commits (fix(scope):, feat(scope):, etc.)
• I searched for existing PRs to make sure this isn't a duplicate
• My PR contains only changes related to this fix/feature (no unrelated commits)
• I've run pytest tests/ -q and all tests pass
• I've added tests for my changes (required for bug fixes, strongly encouraged for features)
• I've tested on my platform: macOS

Documentation & Housekeeping

• I've updated relevant documentation (README, docs/, docstrings) — or N/A
• I've updated cli-config.yaml.example if I added/changed config keys — or N/A
• I've updated CONTRIBUTING.md or AGENTS.md if I changed architecture or workflows — or N/A
• I've considered cross-platform impact (Windows, macOS) per the compatibility guide — or N/A
• I've updated tool descriptions/schemas if I changed tool behavior — or N/A

Code Intelligence

• Analyzed: _is_azure_openai_url (callers: 3 — run_agent.py:1272, agent_init.py:385, chat_completion_helpers.py:1145)
• Blast radius: LOW — substring match is additive, no existing URLs are affected
• Related patterns: Azure URL detection used in gpt-5.x API mode routing (TestGpt5ApiModeRouting)

[alt-glitch]

Duplicate of #47668 — identical fix (extend _is_azure_openai_url() to match ai.azure.com for modern *.services.ai.azure.com resources, same run_agent.py change and test file). #47668 was opened slightly earlier; consolidating there. Both close #47666.

[liuhao1024]

Closing in favor of #47668 — same fix ("ai.azure.com" in url in _is_azure_openai_url()), but #47668 was created 2 minutes earlier and has broader test coverage (includes eastus.api.ai.azure.com pattern and instance-level detection test).