fix(tests): mock search_servers fallback in registry-client UUID-not-found test

[danielmeppiel]

TL;DR

test_find_server_by_reference_uuid_not_found made a real HTTPS call to api.mcp.github.com because only get_server_info was mocked. The Windows runner in build-release.yml can't resolve that hostname and raised socket.gaierror [Errno 11001] getaddrinfo failed, failing the unit-test step. Linux/macOS runners happened to resolve the host so the PR gate (ci.yml, Linux-only) stayed green.

Failing run: https://github.com/microsoft/apm/actions/runs/25651666245

Root cause

find_server_by_reference(reference) in src/apm_cli/registry/client.py:349:

1. If reference is UUID-shaped, calls self.get_server_info(reference).
2. If that raises ValueError, it catches and falls through to self.search_servers(reference) (the name-search fallback).

The test mocked step (1) to raise ValueError but left step (2) unmocked. search_servers builds a requests call to the live registry — on a runner that can't resolve the host, you get a DNS error instead of a ValueError, propagating out of the test as a hard fail.

Fix

Mock search_servers to return [] so the not-found path completes hermetically. Test now exercises both branches of the UUID-not-found path and never touches the network — consistent with the existing .github/instructions/tests.instructions.md rule ("Tests must never hit a real HTTP endpoint").

Why this didn't surface earlier

The Linux PR gate (ci.yml) is Linux-only by design; Windows is covered post-merge by build-release.yml. So this latent network leak only manifested on the Windows post-merge runner.

Validation

uv run --extra dev ruff check src/ tests/        # silent
uv run --extra dev ruff format --check src/ tests/  # silent
uv run pytest tests/unit/test_registry_client.py -x -q
# 31 passed, 5 subtests passed in 2.80s

[Copilot]

Pull request overview

This PR fixes a unit test network leak in the MCP registry client test suite by ensuring the UUID-not-found path is fully mocked and cannot fall through to a real HTTPS request (which was breaking Windows CI due to DNS resolution failures).

Changes:

• Mock SimpleRegistryClient.search_servers in test_find_server_by_reference_uuid_not_found so the UUID lookup fallback path is hermetic.
• Add a CHANGELOG.md entry under ## [Unreleased] / ### Fixed documenting the test fix and the Windows CI impact.

Show a summary per file

File	Description
tests/unit/test_registry_client.py	Extends the UUID-not-found test to also mock the search_servers fallback and assert it is called, preventing real network I/O.
CHANGELOG.md	Records the unit test fix under Unreleased/Fixed with the PR number.

Copilot's findings

• Files reviewed: 2/2 changed files
• Comments generated: 0