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

scheduler.py

@@ -49,11 +49,12 @@ def _run_scheduler() -> None:
             try:
                 main()
                 print("winnow run complete", flush=True)
-            except KeyboardInterrupt:
+            except (KeyboardInterrupt, SystemExit):
                 raise
             except Exception as e:
                 logger.error("winnow run failed: %s", e, exc_info=True)
                 print(f"winnow run failed: {e}", flush=True)
+            cron = croniter(schedule, time.time())
             next_run = cron.get_next(float)
             print(f"Next run: {time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(next_run))}", flush=True)
         time.sleep(min(60, max(1, next_run - time.time())))