feat: improve model update detection logic

Update ModelUpdateRecord.has_update() to only detect updates when a newer remote version exists than the latest local version. Previously, any missing remote version would trigger an update, which could include older versions that shouldn't be considered updates.

- Add logic to find the maximum version ID in library
- Only return True for remote versions newer than the latest local version
- Add comprehensive unit tests for the new update detection behavior
- Update docstring to reflect the new logic

tests/services/test_model_update_service.py

@@ -2,7 +2,11 @@ from types import SimpleNamespace
 
 import pytest
 
-from py.services.model_update_service import ModelUpdateService
+from py.services.model_update_service import (
+    ModelUpdateRecord,
+    ModelUpdateService,
+    ModelVersionRecord,
+)
 
 
 class DummyScanner:
@@ -31,6 +35,49 @@ class DummyProvider:
         return {model_id: self.response for model_id in model_ids}
 
 
+def make_version(version_id, *, in_library, should_ignore=False):
+    return ModelVersionRecord(
+        version_id=version_id,
+        name=None,
+        base_model=None,
+        released_at=None,
+        size_bytes=None,
+        preview_url=None,
+        is_in_library=in_library,
+        should_ignore=should_ignore,
+    )
+
+
+def make_record(*versions, should_ignore_model=False):
+    return ModelUpdateRecord(
+        model_type="lora",
+        model_id=999,
+        versions=list(versions),
+        last_checked_at=None,
+        should_ignore_model=should_ignore_model,
+    )
+
+
+def test_has_update_requires_newer_version_than_library():
+    record = make_record(
+        make_version(5, in_library=True),
+        make_version(4, in_library=False),
+        make_version(8, in_library=False, should_ignore=True),
+    )
+
+    assert record.has_update() is False
+
+
+def test_has_update_detects_newer_remote_version():
+    record = make_record(
+        make_version(5, in_library=True),
+        make_version(7, in_library=False),
+        make_version(6, in_library=False, should_ignore=True),
+    )
+
+    assert record.has_update() is True
+
+
 @pytest.mark.asyncio
 async def test_refresh_persists_versions_and_uses_cache(tmp_path):
     db_path = tmp_path / "updates.sqlite"