fix: increase Immich ML memory to 6GB and add model TTL config

- Increase memory limit from 4GB to 6GB for larger model downloads
- Add MACHINE_LEARNING_MODEL_TTL=300 to keep models in memory longer
- Add MACHINE_LEARNING_MODEL_TTL_POLL_S=10 for faster model unloading checks

Note: Models still failing to download due to network timeouts.
Uploads work but ML features (OCR, facial recognition) fail.

immich/docker-compose.yml

@@ -88,10 +88,12 @@ services:
     environment:
       - MACHINE_LEARNING_CACHE_FOLDER=/cache
       - MACHINE_LEARNING_REQUEST_TIMEOUT=600
+      - MACHINE_LEARNING_MODEL_TTL=300
+      - MACHINE_LEARNING_MODEL_TTL_POLL_S=10
     deploy:
       resources:
         limits:
-          memory: 4G
+          memory: 6G
     networks:
       - immich
     logging: