fix: 10 correctness bugs from full codebase audit

- immich_api: .get("items") or [] handles {"items": null} without crashing len()
- immich_api: catch TypeError alongside ValueError in filter_recent_assets for
  timezone-naive fileCreatedAt comparisons
- scheduler: catch SystemExit in addition to KeyboardInterrupt so cli.main()
  cannot kill the long-running scheduler process
- scheduler: reseed croniter from wall-clock time after each run so overrunning
  jobs don't schedule an immediate back-to-back rerun
- config: reject negative YEARS_FILTER values with a warning, reset to default 10
- frigate_api: return True (not False) for empty filenames list — callers cannot
  distinguish no-op from network failure on False
- jobs: warn on unrecognised STRATEGY value instead of silently falling back
- jobs: casefold ONLY_PEOPLE / SKIP_PEOPLE matching so "john doe" matches "John Doe"
- executor: <= → < so a same-score candidate can fill a freed replacement slot
- embeddings: set _insightface_loaded=True on GPU+CPU double-failure to prevent
  N re-init attempts (one per asset) when InsightFace is broken for a whole run

winnow/executor.py

@@ -384,9 +384,9 @@ def upload_to_frigate(jobs: list[dict]) -> None:
                     # freed slot isn't filled with something worse than what we removed.
                     if min_quality_score_for_slot is not None:
                         file_score = score_map.get(fname)
-                        if file_score is not None and file_score <= min_quality_score_for_slot:
+                        if file_score is not None and file_score < min_quality_score_for_slot:
                             progress.console.print(
-                                f"    [dim]⏭  {fname}: score {file_score:.3f} ≤ freed slot floor"
+                                f"    [dim]⏭  {fname}: score {file_score:.3f} < freed slot floor"
                                 f" {min_quality_score_for_slot:.3f}, skipping[/dim]"
                             )
                             progress.advance(upload_task)