feat: git-based agent version reference and unified outdated badge (0.20.0)

SAC reads latest RDP/ssh-monitor versions from configured git repos for outdated detection, update targets, and settings test-git.

backend/tests/conftest.py

@@ -80,6 +80,30 @@ def db_session(db_engine):
     session.close()
 
 
+@pytest.fixture(autouse=True)
+def mock_agent_git_release(monkeypatch):
+    """API tests must not clone real git repos."""
+    from app.services.agent_git_release import GitReleaseVersions
+
+    empty = GitReleaseVersions(versions={}, fetched_at=None, from_cache=True)
+    monkeypatch.setattr(
+        "app.services.agent_git_release.get_git_release_versions",
+        lambda cfg, **kwargs: empty,
+    )
+    monkeypatch.setattr(
+        "app.api.v1.hosts.get_git_release_versions",
+        lambda cfg, **kwargs: empty,
+    )
+    monkeypatch.setattr(
+        "app.api.v1.settings.get_git_release_versions",
+        lambda cfg, **kwargs: empty,
+    )
+    monkeypatch.setattr(
+        "app.services.agent_update.get_git_release_versions",
+        lambda cfg, **kwargs: empty,
+    )
+
+
 @pytest.fixture
 def client(db_session, monkeypatch):
     monkeypatch.setattr("app.main.bootstrap_api_key", lambda: None)