May 19, 2026: Full harness update

- Model migration: gemma-4-E4B → qwen3.5-9b-vlm
- Dashboard reorder: Usage Over Time + GPU Metrics to top
- Router counter leak fix (gpu_decr in except handler)
- VLM slot upgrade 1→2
- Redis stale key cleanup
- Automated maintenance cron job
- LiteLLM config update
- GPU router config update
- README update

gpu-router-docker.conf

@@ -13,7 +13,7 @@ upstream llmgpu_pool {
 }
 
 upstream ocu_llm_pool {
-    ## RTX 5070 — gemma-4 (Dense 4B) — Ultra-light tasks
+    ## RTX 5070 — qwen3.5-9b-vlm (VLM) — Vision + light tasks
     server 192.168.68.110:8080;
 }
 
@@ -36,7 +36,7 @@ map $http_x_syslog_model $gpu_upstream {
     "heavy"          llmgpu_pool;
     "qwen3.5-27B"    llmgpu_pool;
     "light"          ocu_llm_pool;
-    "gemma-4"        ocu_llm_pool;
+    "qwen3.5-9b-vlm"        ocu_llm_pool;
 }
 
 ## Rate limit zone — 10 req/s per IP, burst of 20