feat: git-based agent version reference and unified outdated badge (0.20.0)

SAC reads latest RDP/ssh-monitor versions from configured git repos for outdated detection, update targets, and settings test-git.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

@@ -1,6 +1,12 @@
 """Agent version parse/compare for outdated highlighting."""
 
-from app.services.agent_version import is_agent_version_outdated, latest_agent_versions_by_product, parse_agent_version
+from app.services.agent_version import (
+    effective_reference_version,
+    host_version_outdated,
+    is_agent_version_outdated,
+    latest_agent_versions_by_product,
+    parse_agent_version,
+)
 from app.models import Host
 from datetime import datetime, timezone
 
@@ -27,6 +33,61 @@ def test_outdated_different_minor_or_major():
     assert is_agent_version_outdated("2.1.0-SAC", latest) is False
 
 
+def test_effective_reference_version_picks_max():
+    assert (
+        effective_reference_version(
+            recommended="2.1.0-SAC",
+            fleet_latest="2.0.6-SAC",
+            min_version="",
+        )
+        == "2.1.0-SAC"
+    )
+    assert (
+        effective_reference_version(
+            recommended="",
+            fleet_latest="2.0.6-SAC",
+            min_version="2.1.0-SAC",
+        )
+        == "2.1.0-SAC"
+    )
+    assert (
+        effective_reference_version(
+            recommended="",
+            fleet_latest="2.0.35-SAC",
+            min_version="",
+        )
+        == "2.0.35-SAC"
+    )
+
+
+def test_host_version_outdated_ssh_vs_git():
+    assert (
+        host_version_outdated(
+            "2.0.6-SAC",
+            recommended="2.1.0-SAC",
+            fleet_latest="2.0.6-SAC",
+        )
+        is True
+    )
+    assert (
+        host_version_outdated(
+            "2.0.6-SAC",
+            recommended="",
+            fleet_latest="2.0.6-SAC",
+        )
+        is False
+    )
+    assert (
+        host_version_outdated(
+            "2.0.6-SAC",
+            recommended="",
+            fleet_latest="2.0.6-SAC",
+            min_version="2.1.0-SAC",
+        )
+        is True
+    )
+
+
 def test_latest_agent_versions_by_product(db_session):
     now = datetime.now(timezone.utc)
     db_session.add_all(