fix: stale __version__, scheduler import order, quality test coverage

- __init__.py: derive __version__ from importlib.metadata instead of
  a hardcoded "0.1.0" that was six releases out of date
- scheduler.py: move winnow.cli import to module top (no more noqa);
  clean up redundant bool variables in check_models
- tests/test_quality.py: 17 tests covering all five quality check
  functions individually plus assess_quality integration cases

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

scheduler.py

@@ -11,6 +11,10 @@ except ImportError:
     print("croniter not installed. Run: uv add croniter")
     sys.exit(1)
 
+# Imported at module level so models loaded during the first run stay
+# resident in memory across all subsequent scheduled runs.
+from winnow.cli import main
+
 SCHEDULE = os.environ["CRON_SCHEDULE"]
 MODELS_DIR = os.environ.get("HF_HOME", "/models/huggingface")
 INSIGHTFACE_BASE = os.environ.get("INSIGHTFACE_HOME", "/models")
@@ -21,18 +25,12 @@ logger = logging.getLogger(__name__)
 def check_models() -> None:
     buffalo = Path(INSIGHTFACE_BASE) / ".insightface" / "models" / "buffalo_l"
     hf_hub = Path(MODELS_DIR) / "hub"
-    buffalo_ok = buffalo.exists()
-    hf_ok = hf_hub.exists() and any(hf_hub.iterdir())
-    if not buffalo_ok:
+    if not buffalo.exists():
         print("  InsightFace Buffalo_L not found — will download on first run", flush=True)
-    if not hf_ok:
+    if not (hf_hub.exists() and any(hf_hub.iterdir())):
         print("  HuggingFace models not found — will download on first run", flush=True)
 
 
-# Import once — models loaded during the first run stay resident in memory
-# for all subsequent scheduled runs, avoiding repeated multi-GB load times.
-from winnow.cli import main  # noqa: E402
-
 NOW = time.time()
 cron = croniter(SCHEDULE, NOW)
 next_run = cron.get_next(float)