fix: audit — score falsy-zero, crop person mismatch, adaptive cap, suppress_output, ldconfig glob, scheduler sleep

- immich_api: `score or confidence` treated 0.0 score as falsy; use explicit None check
- diversity: same falsy-zero fix in _get_face_confidence
- diversity: _crop_face_from_thumbnail scale loop now filters by person_id (was
  using first person's imageWidth/imageHeight regardless of target in group photos)
- jobs: partially-trained auto mode kept limit="auto" for adaptive stopping, then
  caps result to remaining capacity (was converting to int, silently disabling FPS
  adaptive threshold and early-stop)
- embeddings: _suppress_output finally block wraps first dup2 in try/finally so
  stderr is always restored even if stdout restore raises OSError
- Dockerfile: ldconfig find uses python3.* glob instead of hardcoded python3.13
- scheduler: sleep until next_run instead of fixed 60s; eliminates late-fire jitter
  and unnecessary wakeups on long schedules

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

scheduler.py

@@ -49,4 +49,4 @@ while True:
             logger.error(f"winnow run failed: {e}", exc_info=True)
             print(f"winnow run failed: {e}", flush=True)
         next_run = cron.get_next(float)
-    time.sleep(60)
+    time.sleep(max(1, next_run - time.time()))